Vision system for vehicle

ABSTRACT

A vision system for a vehicle includes a forward-viewing camera located behind and viewing through the vehicle windshield, a rear backup camera located at the rear of the vehicle, and a common image processor operable for processing captured image data. A video display screen is located within the interior cabin of the vehicle viewable by a driver of the vehicle. Responsive to the vehicle being shifted into a reverse gear and while the driver is executing a reversing maneuver, video images derived from image data captured by at least the rear backup camera are displayed on the video display screen. When the vehicle is travelling forward, the common image processor processes image data captured by the forward-viewing camera for a lane departure warning system of the vehicle and for a headlamp control system of the vehicle and/or a traffic sign recognition system of the vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/694,225, filed Apr. 23, 2015, now U.S. Pat. No. 9,809,171,which is a continuation of U.S. patent application Ser. No. 12/405,558,filed Mar. 17, 2009, now U.S. Pat. No. 9,019,090, which is acontinuation of U.S. patent application Ser. No. 12/091,525, filed Apr.25, 2008, now U.S. Pat. No. 7,855,755, which is a 371 national phaseapplication of PCT Application No. PCT/US2006/042718, filed Oct. 31,2006, which claims the benefit of U.S. provisional applications, Ser.No. 60/732,245, filed Nov. 1, 2005, Ser. No. 60/759,992, filed Jan. 18,2006, and Ser. No. 60/836,219, filed Aug. 8, 2006, which are herebyincorporated herein by reference in their entireties; and U.S. patentapplication Ser. No. 12/405,558 is a continuation-in-part of U.S. patentapplication Ser. No. 11/935,800, filed Nov. 6, 2007, now U.S. Pat. No.7,571,042, which is a continuation of U.S. patent application Ser. No.11/624,381, filed Jan. 18, 2007, now U.S. Pat. No. 7,490,007, which is acontinuation of U.S. patent application Ser. No. 10/645,762, filed Aug.20, 2003, now U.S. Pat. No. 7,167,796, which claims priority of U.S.provisional applications, Ser. No. 60/406,166, filed Aug. 27, 2002, Ser.No. 60/405,392, filed Aug. 23, 2002, and Ser. No. 60/404,906, filed Aug.21, 2002; and U.S. patent application Ser. No. 10/645,762 is acontinuation-in-part of U.S. patent application Ser. No. 10/456,599,filed Jun. 6, 2003, now U.S. Pat. No. 7,004,593; and U.S. patentapplication Ser. No. 10/645,762 is a continuation-in-part of U.S. patentapplication Ser. No. 10/287,178, filed Nov. 4, 2002, now U.S. Pat. No.6,678,614, which is a continuation of U.S. patent application Ser. No.09/799,414, filed Mar. 5, 2001, now U.S. Pat. No. 6,477,464, whichclaims priority of U.S. provisional application Ser. No. 60/187,960,filed Mar. 9, 2000; and U.S. patent application Ser. No. 11/624,381 isalso a continuation-in-part of U.S. patent application Ser. No.10/755,915, filed Jan. 13, 2004, now U.S. Pat. No. 7,446,650, which is acontinuation of U.S. patent application Ser. No. 09/793,002, filed Feb.26, 2001, now U.S. Pat. No. 6,690,268, which claims benefit of U.S.provisional applications, Ser. No. 60/263,680, filed Jan. 23, 2001, Ser.No. 60/243,986, filed Oct. 27, 2000, Ser. No. 60/238,483, filed Oct. 6,2000, Ser. No. 60/237,077, filed Sep. 30, 2000, Ser. No. 60/234,412,filed Sep. 21, 2000, Ser. No. 60/218,336, filed Jul. 14, 2000, and Ser.No. 60/186,520, filed Mar. 2, 2000; and U.S. patent application Ser. No.11/624,381 is also a continuation-in-part of U.S. patent applicationSer. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381,which claims priority from U.S. provisional applications, Ser. No.60/346,733, filed Jan. 7, 2002, Ser. No. 60/263,680, filed Jan. 23,2001, Ser. No. 60/271,466, filed Feb. 26, 2001, and Ser. No. 60/315,384,filed Aug. 28, 2001, and which is a continuation-in-part of U.S. patentapplication Ser. No. 09/793,002, filed Feb. 26, 2001, now U.S. Pat. No.6,690,268.

FIELD OF THE INVENTION

The present invention relates to interior rearview mirror assembliesand, more particularly, to an interior rearview mirror assembly having adisplay device for viewing through the reflective element of theinterior rearview mirror assembly.

BACKGROUND OF THE INVENTION

Conventional interior rearview mirrors for vehicles typically include aprismatic substrate having a first surface facing a viewer of the mirrorwho is seated in the vehicle and a second, reflecting surface (typicallysilver coated) opposite the first surface. Electrically variablereflectance mirrors may comprise electro-optic reflective elementassemblies, which comprise a first or front substrate and a second orrear substrate (typically flat glass substrates) with an electro-opticmedium (typically an electrochromic medium) disposed between the frontsubstrate and the rear substrate. Visible light transmission through theelectro-optic medium is controllable by applying an electrical voltagethereto. Such a twin substrate electro-optic element has four surfaces;a first surface frontmost on the front or first substrate and a secondsurface opposing the first surface and also on the first substrate. Therear or second substrate has a third surface and an opposing fourthsurface. The second surface of the front substrate is commonly coatedwith a transparent electrical conductor, such as indium tin oxide. Thethird surface of the rear substrate is commonly coated with a metallicreflecting/electrical conductor, such as a layer of silver or of asilver alloy or a stack layer of ITO/Ag/ITO or the like, or it may becoated with a transparent electrical conductor, such as indium tinoxide, while the opposing surface of the second or rear substrate (thefourth surface) may be coated with a mirror reflector, such as silvermetal layer. To form an electro-optical mirror element, the secondsurface of the front substrate is arranged opposing the third surface ofthe rear substrate and the electro-optic medium is disposed between thesecond surface of the front substrate and the third surface of the rearsubstrate. It is common to include a display device at the mirrorassembly, such as rearward of the second or rear substrate and so behindits fourth surface so that its display image is viewable through thesubstrates by a person seated within the interior cabin of the vehicle(such as a driver of the vehicle) viewing the interior rearview mirrorassembly when it is normally mounted to the windshield or to the headerof the vehicle.

It is thus known to have a display device, such as a video displaydevice capable of displaying a video image captured by a video imagingdevice, such as a video camera, disposed behind and visible through aninterior rearview mirror element, such as, for example, displays of thetypes disclosed in U.S. Pat. Nos. 5,668,663; 5,724,187; 5,956,181 and6,690,268, which are hereby incorporated herein by reference in theirentireties. It is thus known to have a covert display device (a.k.a. adisplay-on-demand display device), such as a covert video displaydevice, disposed behind and thus visible through a transflectiveinterior rearview mirror element, such as an electrochromictransflective interior rearview mirror element, such as the typesdescribed in U.S. Pat. Nos. 5,668,663; 5,724,187 and 6,690,268, whichare hereby incorporated herein by reference in their entireties.

It has also been suggested to use a polymeric transflective film orlayer or element at the fourth surface of a rearview mirror reflectiveelement. For example, it has been suggested that an all-polymeric filmor element that is both significantly reflecting and substantiallytransmitting, such as PRM material such as described in U.S. Pat. No.5,724,187, which is hereby incorporated herein by reference in itsentirety, or a polymer-based film having reflective properties, such asthe multilayer reflective film described in U.S. Pat. No. 6,352,761;and/or U.S. Pat. Pub. No. US 2005/0174645, published Aug. 11, 2005 whichare hereby incorporated herein by reference in their entireties, be usedas a mirror reflector in an automotive rearview mirror. Such anall-polymeric specular mirror film is available from 3M of Minneapolis,Minn. under the tradename Vikuiti™ Enhanced Specular Reflector Film(ESR), which consists of over 300 polymers layers of differentrefractive (typically alternating) indexes that create a mirror finish.

However, successful commercialization of covert video displays that aredisposed behind and whose presence behind the mirror reflector isprincipally visible/discernible to the driver or other occupant of thevehicle only when the display image is actuated has hitherto beenimpaired by display image washout during higher ambient lightingconditions, such as daylight lighting conditions, particularly on asunny day. Therefore, there is a need in the art for an improved covertvideo imaging display device for an interior rearview mirror assembly ofa vehicle that overcomes shortcomings of the prior art.

SUMMARY OF THE INVENTION

The present invention provides an interior electro-optical rearviewmirror assembly with a video display (or other display) at or behind therearmost or fourth surface of an electro-optical (EO) variablereflectivity element of the mirror assembly, whereby the display isviewable through the electro-optical element by a person viewing theinterior rearview mirror assembly.

According to an aspect of the present invention, an electro-optical (EO)variable reflectivity element of the mirror assembly preferablycomprises a front (first) and a rear (second) substrate have (countingfrom the frontmost surface of the front substrate) a first surface, asecond surface, a third surface and a fourth surface. The EO medium[preferably an electrochromic (EC) medium] is disposed between thesecond surface of the front substrate and the third surface of the rearsubstrate. Preferably, a high transmitting/high electrical conductingtransparent conducting coating is coated onto the second surface of thefront substrate and onto the third surface of the third surface of therear substrate so light transmission through the front and rearsubstrates with the EO medium therebetween but with the EC medium in itshigh light transmitting or bleached state (commonly its unpowered state)is optimized or maximized. A significantly visible light reflecting andsignificantly visible light transmitting and significantly visible lightpolarizing element or film is disposed behind the fourth surface of theEC element and preferably contacts, and most preferably is opticallycoupled to, the fourth (rearmost) surface (which typically is glass witha refractive index of about 1.52, as measured at the Sodium D line).This visible light transflecting/polarizing element or film (thatpreferably is an all-polymeric construction comprising hundreds ofindividual very thin polymer layers one on top of another and withdifferent, often alternating, refractive indexes) polarizes (preferablylinearly polarizes) visible light passing therethrough and alsosubstantially reflects visible light incident thereon [preferably havinga visible light reflectivity of at least about 50 percent reflectance(as measured in accordance with SAE J964a, which is hereby incorporatedherein by reference in its entirety), more preferably having a visiblelight reflectivity of at least about 60 percent reflectance of lightincident thereon and most preferably having a visible light reflectivityof at least about 70 percent reflectance of light incident thereon] andalso having at least about 25% T transmission to visible light (asmeasured in accordance with SAE J964a), more preferably at least about35% T and most preferably at least about 45% T, but preferably having atransmissivity to visible light of less than about 60% T (as measured inaccordance with SAE J964a).

According to another aspect of the present invention, a video displaydevice (or other display device) is disposed behind the visible lighttransflecting/polarizing element or film. The video display devicecomprises a video screen element and a backlighting element. The videoscreen element preferably attaches to (and most preferably opticallycouples with) the rear of the visible light transflecting/polarizingelement (when the visible light transflecting/polarizing element isattached to and/or disposed behind the fourth surface of the ECelement). The backlighting element is disposed to the rear of the videoscreen so that visible (or other) light emitted from the backlightingelement (when it is electrically powered) passes through the videoscreen element. Preferably, the video screen polarizes this light (morepreferably linearly polarizes) along a light polarization axis thatsubstantially matches the principal light polarization axis of thevisible light transflecting/polarizing element. Also, the video screenelement and visible light transflecting/polarizing element are mutuallyorientated/arranged so that their principal light polarization axes areat least substantially parallel so as to maximize transmission ofpolarized light through such combination. Thus, light emitted from thebacklighting element and passing through the video screen element issubstantially transmitted through the visible lighttransflecting/polarizing element (and thus is substantially viewable tothe driver through the electro-optical element), while visible lightincident on the mirror assembly from the rear of the vehicle (thatpasses through the electro-optical element) is significantly reflectedback to the driver of the vehicle by the visible lighttransflecting/polarizing element.

According to another aspect of the present invention, an interiorelectro-optic rearview mirror assembly for a vehicle includes areflective element having a rear (fourth) surface having a reflectivelayer thereat and a display element at the rear surface of thereflective element. The reflective element includes a visible lighttransflecting/polarizing element at the rear surface of the reflectiveelement at a display opening or window formed in the reflective layer ofthe reflective element. A backlit video display element is disposed atthe window formed at the reflective layer. The visible lighttransflecting/polarizing element or film is disposed between the displayelement and the rear (fourth) surface of the reflective element.

The display element preferably comprises a polarizing display element,such as a thin film transistor (TFT) liquid crystal display (LCD) videodisplay element, and includes an illumination source for backlighting oremitting illumination through the TFT LCD video display element. Thevisible light transflecting/polarizing element is disposed so that thepolarizing angle or axis of the visible light transflecting/polarizingelement is substantially similar to the polarizing angle or axis of thepolarizing display element.

According to another aspect of the present invention, an interiorrearview mirror assembly includes a display disposed behind thereflective element so as to display information through the reflectiveelement for viewing by the driver of the vehicle. The mirror assemblyincludes a thermal conducting element or heat sink or heat dissipatingdevice or element disposed at and in substantial or intimate contactwith the display device or element, whereby heat generated by thedisplay device during operation thereof is drawn away from the displaydevice by the thermally conducting element and to an exterior of themirror assembly, where the heat may be dissipated at or to the rear ofthe mirror assembly and outside of the mirror assembly. The thermallyconducting element may be exposed at the rear mirror casing, and may beexposed in a manner whereby the thermally conducting element is notreadily discernible to a person viewing the mirror casing, such as by aperson viewing the mirror casing from outside the vehicle and throughthe vehicle windshield when the mirror assembly is mounted at thevehicle, such as at an interior surface of the vehicle windshield.

Therefore, an aspect of the present invention provides an interiorelectro-optic (such as an electrochromic) rearview mirror assembly witha backlit display element and may include a visible lighttransflecting/polarizing element or film disposed at a rear surface orfourth surface of the electro-optical element. The visible lighttransflecting/polarizing element or film functions to allow substantialtransmissivity of at least partially polarized light from the displayelement to pass through the electro-optical element for viewing by aperson (such as a driver of the vehicle) viewing the mirror assembly,while providing a desired degree of reflectance of light incident on thereflective element so that the driver can use the electro-optic mirrorto see rearward when driving on a highway. The display information (suchas a video display of the area immediately to the rear of the vehicle ascaptured by a video camera mounted, such as at a rear license plateholder, at the rear of the vehicle so as to display to the driver whenhe/she may be reversing the vehicle any obstacles or persons immediatelyto the rear of the vehicle) thus may be readily viewable through and atthe reflective element when the display element is activated orenergized, but the display element and display area is substantially notreadily viewable or not discernible by a person viewing the reflectiveelement when the display element is deactivated or de-energized so as tobe substantially covert. The display element may comprise a TFT LCDvideo display element and may at least partially linearly polarizeslight passing therethrough, whereby the visible lighttransflecting/polarizing element or film is applied or disposed betweenthe display element and the rear surface of the electro-optical elementso that the polarization axes of the display element and of the visiblelight transflecting/polarizing element or film are generally or,preferably, substantially aligned. The reflective element and display ofthe present invention thus provides enhanced transmission of theillumination by the display element to reduce display image washout,while providing the desired degree of reflectivity of light incident onthe reflective element. Optionally, and desirably, the mirror assemblymay include a thermal conducting element in contact with the displayelement or display module and configured to draw heat from the displayelement or module and to dissipate the heat at an exterior area of themirror assembly.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an interior rearview mirror assemblyincorporating a display in accordance with the present invention;

FIG. 2 is a sectional view of an electro-optic element for an interiorrearview mirror assembly of the present invention, with a visible lighttransflecting/polarizing element or film disposed at a polarizingdisplay element of the mirror assembly;

FIG. 3 is a schematic showing an exemplary polarizing angle of thedisplay element and visible light transflecting/polarizing element orfilm of the present invention;

FIG. 4 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIGS. 5A and 5B are schematics showing steps of a process suitable formanufacturing an electro-optic element in accordance with the presentinvention;

FIG. 6 is a schematic showing the optical characteristics of a broadbandtransflective substrate in accordance with the present invention;

FIG. 7 is a sectional view of a display device useful with the mirrorelement of the present invention;

FIG. 8 is a plan view of the backlighting elements of the display deviceof FIG. 7;

FIG. 9 is a visible light transmission spectral scan of a polarizingtransflective film suitable for use with the present invention;

FIG. 10 is a visible light transmission spectral scan of the Vikuiti™polarizing transflective film of FIG. 9 as combined with anelectro-optic mirror element in accordance with the present invention

FIG. 11 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 12 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 13 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 14 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 15 is a plan view of a vehicle showing a field of view of a typicalinterior rearview mirror assembly;

FIG. 16 is a front elevation of an enlarged asymmetrical mirror assemblyin accordance with the present invention;

FIG. 17 is a plan view of a vehicle showing the field of view of themirror assembly of FIG. 16;

FIG. 18 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 19 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIG. 20 is a sectional view of another electro-optic element for aninterior rearview mirror assembly of the present invention;

FIGS. 21 and 22 are charts indicating typical brightness or luminance ofdifferent lighting conditions;

FIG. 23 is a sectional view of another mirror reflector element inaccordance with the present invention;

FIG. 24 is a spectral chart showing the luminosity of light through thereflector element of FIG. 23;

FIG. 25 is a spectral chart showing the transmission of differentwavelengths of light through the mirror reflector element of FIG. 23;

FIG. 26A is a front elevation of a mirror assembly in accordance withthe present invention, with the video display device deactivated;

FIG. 26B is a front elevation of the mirror assembly of FIG. 26A, withthe video display device activated;

FIG. 27 is an exploded perspective view of a mirror assembly of thepresent invention;

FIG. 28 is a front elevation of the mirror assembly of FIG. 27;

FIG. 29 is a rear elevation of the mirror assembly of FIG. 28;

FIG. 30A is a sectional view of the mirror assembly taken along the lineA-A in FIG. 28;

FIG. 30B is a sectional view of the mirror assembly taken along the lineB-B in FIG. 28;

FIG. 30C is a sectional view of the mirror assembly taken along the lineC-C in FIG. 28;

FIG. 30D is a sectional view of the mirror assembly taken along the lineD-D in FIG. 28;

FIG. 30E is a sectional view of the mirror assembly taken along the lineE-E in FIG. 28;

FIG. 30F is a sectional view of the mirror assembly taken along the lineF-F in FIG. 28;

FIG. 31A is a plan view of a backing plate of the mirror assembly of thepresent invention;

FIG. 31B is an opposite plan view of the backing plate of FIG. 31A;

FIG. 32A is an inside plan view of the rear mirror casing of the mirrorassembly of FIG. 27;

FIG. 32B is an outside plan view of the rear mirror casing of FIG. 32A;

FIG. 33 is a perspective view of a display module in accordance with thepresent invention;

FIG. 34 is a perspective view of a portion of the display module, with acorner portion cut away to show additional details;

FIG. 35 is a sectional view of the display module of FIG. 33;

FIG. 36A is a perspective and partial sectional view of the displaymodule of FIG. 33;

FIG. 36B is another perspective and partial sectional view of thedisplay module of FIG. 33, taken along a line extending longitudinallyalong the display module;

FIG. 37 is a sectional view of the display module of FIG. 33;

FIG. 38A is a perspective view of a portion of the display modulecasing, showing flexible retaining beams with retaining projectionsthereon;

FIG. 38B is an enlarged perspective view of the display module casingportion of FIG. 38A;

FIG. 39A is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 39B is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 39C is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 39D is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 39E is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 39F is a sectional view of a display screen and display module at amirror reflective element in accordance with the present invention;

FIG. 40 is a schematic of a video display system of a mirror assembly inaccordance with the present invention;

FIG. 41A is a plan view of the mirror assembly and display module of thepresent invention, showing a display module mounting device forpositioning the display module at the rear of the reflective element ofthe mirror assembly;

FIG. 41B is a side elevation of the mirror assembly and display moduleof FIG. 41A;

FIG. 41C is a sectional view of the mirror assembly and display moduletaken along the line C-C in FIG. 41A;

FIG. 42 is a perspective view of another mirror assembly, with a heatdissipating element in accordance with the present invention;

FIG. 43 is a perspective view of another mirror assembly, with a heatdissipating element in accordance with the present invention;

FIG. 44 is a perspective view of another mirror assembly, with a heatdissipating element in accordance with the present invention; and

FIG. 45 is a plan view of a vehicle incorporating an image and displaysystem in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depictedtherein, an interior rearview mirror assembly 10 for a vehicle includesan electro-optic element assembly or cell 12 and a display device 14 ata rear surface of the electro-optic element 12 for displayinginformation at a display area 15 of the reflective element (FIGS. 1 and2). Display device 14 is disposed at the rear surface of theelectro-optic element 12, with a visible light transflecting/polarizingelement or film or layer 16 disposed between the display device and therear surface of the electro-optic element 12. Visible lighttransflecting/polarizing element or film 16 functions to substantiallytransmit polarized illumination emitted from the display device 14 thatthen passes through electro-optic element 12 while reflecting othersubstantially non-polarized illumination or light (typically sunlight byday or moonlight/vehicle headlamp lighting/street lighting and the likeby night) that is incident on electro-optic element 12 from its front(first surface) when interior rearview mirror assembly 10 is mountedwithin the interior cabin of the vehicle. The visible lighttransflecting/polarizing element or film 16 thus provides asubstantially reflective layer at the display area 15, while beingtransmissive of light or illumination emitted by display device 14, asdiscussed below.

In the illustrated embodiment, electro-optic element 12 of interiorrearview mirror assembly 10 comprises an electro-optic element assemblyor cell, such as an electrochromic element or cell. Electro-opticelement assembly 12 includes a front substrate 18 and a rear substrate20 spaced from front substrate 18 (with the substrates both beingsubstantially light transmitting and fabricated from glass or from anoptical plastic, such as acrylic or polycarbonate or CR39 or a COColefin or the like). The electro-optic element 12 includes anelectro-optic medium 22 (such as an electrochromic medium) andtransparent conductive or semi-conductive layers 24, 26 (such asdescribed below) sandwiched between the substrates 18, 20 (with thetransparent conductive layer 24 disposed at a rear surface 18 a of frontsubstrate 18 [the second surface of the laminate electro-opticalelement] and the transparent conductive layer 26 disposed at the frontsurface 20 a of rear substrate 20 [the third surface of the laminateelectro-optical element]). Desirably, the conductive layers 24, 26 maybe selected to be substantially transparent and with little or nopolarization effect. For example, the conductive layers 24, 26 maycomprise an indium tin oxide (ITO) material or a thin metallic layersandwiched between two transparent conductive layers (a TC/M/TC stack oflayers) such as ITO/Metal/ITO (for example, ITO/Ag/ITO) or a doped tinoxide or a doped zinc oxide or the like, so as to provide the desiredconductivity and transparency at the second and third surfaces of thefourth surface reflector reflective element or cell. An electrical sheetresistance of less than about 20 ohms/square is preferred for suchtransparent conductor layers; more preferably less than about 15ohms/square and most preferably less than about 10 ohms/square, whilevisible light transmission through such transparent conductive coatedsubstrates is preferably at least about 70% T, more preferable at leastabout 75% T and most preferably is at least about 80% T. An epoxy sealmaterial 28 or the like is applied between the substrates to define thecavity for the electrochromic medium and to adhere the substratestogether.

The electro-optic optic element 12 is configured and constructed so thatvisible light passing therethrough is substantially to wholly unchangedin its light polarization character. Thus, unpolarized light incident onthe front substrate and passing through the front substrate and throughthe electro-optic medium and through the rear substrate exits the rearsubstrate still substantially or wholly unpolarized, and does soregardless of whether the electro-optical medium is in its clear orbleached or day high light transmitting state (for automotive mirrors,typically its non-electrically powered state) or whether theelectro-optical medium is in its dimmed or anti-glare or darkened,reduced light transmitting state (for automotive mirrors, typically itselectrically powered state). And polarized light (such as linearlypolarized light or circularly polarized light or elliptically polarizedlight) incident on the rear substrate and passing through the rearsubstrate and through the electro-optic medium and through the frontsubstrate exits the front substrate still substantially or whollypolarized, and does so regardless of whether the electro-optical mediumis in its clear or bleached or day high light transmitting state (forautomotive mirrors, typically its non-electrically powered state) orwhether the electro-optical medium is in its dimmed or anti-glare ordarkened, reduced light transmitting state (for automotive mirrors,typically its electrically powered state). Thus, electrochromic mediaand constructions are preferred for electro-optic element 12. Liquidcrystal electro-optical media and constructions (such are disclosed inthe likes of WO 2005/050267 or U.S. Pat. Publication No. US2005/0185278, published Aug. 25, 2005, which are hereby incorporatedherein by reference in their entireties) that change the state ofpolarization of light passing therethrough by use of the likes of acholesteric liquid crystal electro-optic medium 22 are not suited to thepresent invention.

Electro-optic element 12 has a reflector at its fourth surface (20 b)and may include an opaque and/or reflective backing layer or film 30 atits rear or fourth surface. In the illustrated embodiment of FIG. 2,backing layer 30 is disposed at a rear surface of the polarizingtransflective polymeric film 16. The backing layer 30 has a window oropening or cut-out or aperture 30 a formed therethrough so that displaydevice 14 may be operable to emit illumination or light through thewindow and through the electro-optical element 12 for viewing by aperson viewing the interior rearview mirror assembly. Window 30 athrough backing layer 30 thus helps define the viewing area or displayarea 15 at the electro-optic element 12.

Visible light transflecting/polarizing element or film 16 is attached tothe rear surface 20 b of rear substrate 20, such as via an opticalcoupling layer 32, such as an optical adhesive, such as an acrylic or anacrylate or an epoxy or a urethane or the like. For example, the visiblelight transflecting/polarizing element or film 16 may be attached to therear surface 20 b of rear substrate 20 via an optical index matchingadhesive, such as an optical epoxy or optical acrylic (such as byutilizing aspects of the reflective element described in U.S. patentapplication Ser. No. 10/993,302, filed Nov. 19, 2004, now U.S. Pat. No.7,338,177, which is hereby incorporated herein by reference in itsentirety). The visible light transflecting/polarizing element or filmmay comprise any suitable visible light transflecting/polarizing elementor film, such as a polarizing reflective film commercially availablefrom 3M of Minneapolis, Minn. under the brand name Vikuiti™, such as 3MVikuiti™ Polarizing Reflective Film (BEF-RP or BEF-P) or the like. Suchall-polymeric polarizing transflective films comprise hundreds of verythin alternating layers of polymer material of different refractiveindexes. For example, the Vikuiti™ Dual Brightness Enhancement Films(DBEF) are a complex film consisting of over 800 polymer layers and arereflecting to visible light, are transmitting to visible light and arepolarizing to visible light.

In the illustrated embodiment, display device 14 includes anillumination source(s) 34 that functions as a backlighting element fordisplay element 36. Illumination source(s) 34 may comprise one or morelight emitting diodes (LEDs) [such as a plurality of LEDs, such as highintensity LEDs of the types described in U.S. patent application Ser.No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381, whichis hereby incorporated herein by reference in its entirety], or maycomprise cold-cathode fluorescent sources, laser diode sources,electroluminescent sources, or the like, and may be electricallyactivatable or operable or energizable to backlight or illuminate thedisplay element 36. Display element 36 may comprise a video displayelement, such as a thin film transistor (TFT) liquid crystal display(LCD) video screen or the like. The display device 14 is positioned atthe rear surface of the reflective element and at the window 30 a formedin or through the backing layer 30, so that the image displayed bydisplay device 14 (such as a video image of a reversing event when thedriver engages reverse gear) may be visible to the driver by he/shelooking through the window 30 a in backing layer 30 when he/she isviewing through the substrates 18, 20 while viewing the reflectiveelement of the interior rearview mirror assembly. Preferably, thedisplay element 36 is attached or adhered at the polarizingtransflective polymeric film 16, such as by an optical coupling layer38, such as an optical adhesive, such as the types described above.However, but less preferably, polarizing transflective polymeric film 16may be spaced from and stood off from fourth surface 20 b without anyindex matching layer or means.

Optionally, and as shown in FIG. 4, the backing layer 30′ may bedisposed at the rear, fourth surface 20 b of rear substrate 20 of anelectro-optic element 12′ and the polarizing transflective polymericfilm 16′ may be disposed at the window region of the backing layer 30′and adhered to the rear surface 20 a of rear substrate 20 via an opticalcoupling layer 32′, such as an optical adhesive, such as acrylic oracrylate or epoxy or urethane or the like, such as described above andthat has an refractive index of about 1.48 to about 1.55 and preferably,close to about 1.52. The display device 14′ may be adhered or attachedat the visible light transflecting/polarizing element or film 16′, suchas via an optical coupling layer 38′, such as an optical adhesive or thelike, such as described above. The display device 14′ and electro-opticelement 12′ may be otherwise substantially similar to display device 14and electro-optic element 12 discussed above, such that a detaileddiscussion of the display devices and electro-optic elements will not berepeated herein. The common features or elements or components of thedisplay devices and electro-optic elements are shown in FIGS. 2 and 4with the same reference numbers. The reflectance off the backing layer30′ in the construction as shown in FIG. 4 may be chosen so that themirror reflectivity at the portion of the electro-optic element 12 wherethe display element is disposed is matched to that of thesurrounding/other portions of the electro-optic element 12 where thedisplay element is not disposed so that the covert presence of displaydevice is best achieved when the display device is in its non-energized(non-light emitting) mode. By matching the reflectance seen by thedriver at the display area to that of the surrounding non-display areas,the consumer is least aware of the overt presence of the video screenuntil it is powered so as to display its video image.

The electro-optic element, display device and polarizing transflectiveelement of the present invention thus provides a transflective covertdisplay (on-demand type of display) that is viewable by a person viewingthe interior rearview mirror assembly on a sunny day when the displaydevice is activated or energized, but that is generally non-viewable ornon-discernible when viewed when the display device is deactivated orde-energized. Typically, it is desirable to have an electro-opticalelement/polarizing transflective element combination that has as high avisible light transmissivity as is possible so that the display imagebeing displayed (when the backlighting element is actuated and is lightemitting) is readily viewable to the driver, in order to reduce imagewashout during high ambient lighting conditions, such as typically occuron a sunny day. In this regard, visible light transmission through theelectro-optical element (in its high transmission or bleached state)combined with the polarizing transflective element therebehind ispreferably at least about 15% T (as measured in accordance with SAEJ964a, which is hereby incorporated herein by reference in itsentirety), more preferably is at least about 25% T and most preferablyis at least about 35% T. However, if this combination is overly lighttransmitting and with the EC element in its bleached state (typicallyits unpowered state), then the covert presence of the likes of a videodisplay element therebehind may be compromised and so it is preferablethat light transmission through electro-optical element or cell 12 incombination with polarizing transflective polymeric film 16 be less thanabout 45% T, more preferably be less than about 40% T and mostpreferably be less than about 35% T. It is also desirable to selectelectro-optical element or cell 12 in combination with polarizingtransflective polymeric film 16 to provide a desired degree ofreflectance off the interior electro-rearview mirror of the presentinvention so that the driver can adequately use the mirror to provide arearward view when driving on the highway. Thus the EO mirror assemblyshould deliver a reflectivity of at least 40% R (as measured using SAEJ964a) of light incident thereon and more preferably, deliver to thedriver a mirror reflectivity at least about 45% R and most preferably,deliver to the driver a mirror reflectivity at least about 55% R oflight incident on the mirror reflective element, including at thedisplay area of the reflective element.

There is typically a tension or challenge in optimizing or maximizingreflectance and transmissivity, since the greater the transmissivity ofthe transflective polarizing element, the more visible the displaydevice may be when it is not activated or energized. By providing abacklit TFT LCD display element and a polarizing transflective layer orfilm at the rear of the reflective element, the present inventionprovides enhanced transmission of polarized light through theelectro-optical element to be seen by the driver, while enablingenhanced reflectivity of the likes of sunlight or moonlight or urbanstreet lighting incident on the electro-optical reflective mirrorelement of the interior mirror assembly that the driver relies on forhis or her rearward driving task when using the interior mirror whiledriving.

Display screens of the display device [such as a TFT LCD video displayelement or the like] act as a polarizer (typically as a linearpolarizer) to the light emitted by the illumination source or sources[such as light emitting diodes (LEDs), cold-cathode fluorescent sources,laser diode sources, electroluminescent sources or the like] that arebacklighting the display screen. Thus, light emitted by the illuminationsource, when passed through the TFT LCD video display screen element, ispartially or substantially linearly polarized by the TFT LCD videodisplay element so that linearly polarized light (such as light that issubstantially polarized along a particular angle or axis) is emitted bythe display device. Thus, when the principal polarization axis of thepolarizing transflective element is aligned so as to be substantiallyparallel with that of the light transmitted through the video screen,light transmission through the mirror assembly is optimized. Because thedisplay illumination or light is polarized by the TFT LCD video displayelement, the display illumination intensity that would pass throughpolarizing transflective element would be reduced (in accordance withMalus's Law), unless the respective polarization axis are aligned.Correspondingly, daylight incident on the interior mirror during drivingon the likes of a sunny day is largely unpolarized and so the use of apolarizing transflective element as the mirror reflector (at least atthe portion of the interior mirror where the display element isdisposed) helps reduce displayed image wash-out during day-time driving.Thus, by providing a visible light transflecting/polarizing element orfilm between the display element and the electro-optic element, thevisible light transflecting/polarizing element or film (which is alignedor substantially aligned with the TFT LCD video display element suchthat its polarization axis or angle substantially matches thepolarization axis or angle of the TFT LCD video display element, asdiscussed below) may be substantially transmitting for the polarizedlight emitted by the display device, yet may provide substantialreflectance to other light incident on the mirror reflective elementduring daytime driving. The present invention thus may provide asubstantial visible light transmission and a significantly visible lightreflectance at the display area of the interior mirror assembly.Although described as a linearly polarized device, it is envisioned thata similar approach could be taken for a circularly polarized displaydevice or other forms or polarized light such as elliptically polarizedlight, while remaining within the spirit and scope of the presentinvention.

The visible light transflecting/polarizing element or film or layermaterial may be selected so as to provide a desired degree ofreflectance of light incident thereon, such as at least approximately 50percent reflectance of light incident thereon (as established via SAEJ964a), more preferably at least approximately 55 percent reflectance oflight incident thereon, more preferably at least approximately 60percent reflectance of light incident thereon, and more preferably atleast approximately 65 percent reflectance of light incident thereon.And visible light transmission through the visible lighttransflecting/polarizing element or film or layer material is preferablyat least about 25% T (as measured in accordance with SAE J964a, which ishereby incorporated herein by reference in its entirety), morepreferably is at least about 35% T and most preferably is at least about45% T, but to help preserve the covert placement of the display deviceat the display area, visible light transmission through the visiblelight transflecting/polarizing element or film or layer material ispreferably less than about 60% T, more preferably be less than about 55%T and most preferably be less than about 50% T. As in FIG. 2 (where thevisible light transflecting/polarizing element is disposed substantiallybehind the entire fourth surface area of the electro-optic element 12),the visible light transflecting/polarizing element forms the mirrorreflector. We find that the reflectance at the display area may behigher than that at the surrounding non-display area, and so the backinglayer 30 may be adapted/configured to reflect light to any degree neededto increase reflectivity at the non-display area so as to better blendin the display area to the non-display area in order to enhance thecovert placement of the display element at the display area. In thelikes of the construction shown in FIG. 4 (where the visible lighttransflecting/polarizing element is disposed only behind the displayarea of the fourth surface area of the electro-optic element 12),backing layer 30′ is principally light reflecting with its reflectivitychosen to match that at the display area (note that backing layer 30′,that is disposed other than at the display area, may be a metallic thinfilm coating such as of chromium or titanium or ruthenium (or alloysthereof) or may be a thin film of silicon or a silicon alloy or may be acoated plastic film with its reflective properties chosen to achieve amatch or substantial match in reflectivity between the display andnon-display areas). If there is a desire to only moderately enhancereflectivity, use can be made of a thin reflecting coating (such as ofCr or Ti or Ru or Inconel or Hastelloy or Si) of physical thickness lessthan about 250 angstroms (i.e., less than about 25 nanometers) or lower(such as in the range of about 75 angstroms to about 150 angstroms) atother than at the display area. Or the likes of an interferencereflector can be used [such as a transflective blue mirror multilayerreflector stack such as (from the glass surface) about a 44.78 nm layerof TiO₂ overcoated with about a 82.63 nm layer of SiO₂ overcoated withabout a 48.59 nm layer of TiO₂; whereby such a second-surface coatedglass substrate has a second-surface reflectivity of about 45 percent toabout 50 percent or thereabouts, and a visible light transmission inexcess of about 30 percent].

The display area thus may substantially match the reflectivity of therest of the reflective area of the reflective element so that thedisplay area is not readily discernible by a person viewing the interiorrearview mirror assembly when the display element is deactivated orde-energized.

An exemplary display device for use with the present invention is shownin FIG. 7. Display device 70 comprises a video screen 77 (such as anOptrex 3.5 inch TFT LCD screen with extended temperature range LC fluidand higher temperature resisting polarizing films such that the LCDvideo screen can display video images, and resist exposure to, at leastover a temperature range where automobiles may operate such as fromabout −20 degrees Celsius to about 85 degrees Celsius, or thereabouts)and a backlighting element 78 (such as two U-shaped cold cathodefluorescent light (CCFL) devices, as discussed below). Video screen 77has a visible light transmission in the about 5% T to about 10% T range;more preferably in the about 10% T to about 15% T range, or higher.Brightness enhancement films 75, 75′ (such as Vikuiti™ BEF films from3M) and a light diffuser sheet 73 (such as a hazed or diffuse-lighttransmitting plastic diffuser or sheet) are provided between videoscreen 77 and backlighting element 78. As illustrated (and as can beseen with reference to FIG. 8), two cold cathode fluorescent lightsources 81, 81′ are used as backlighting for video screen 77. Whenmeasured by placing the video screen into a reflectometer and measuringin accordance with SAE J964a, the reflectance of the particular videoscreen 77 used was about 5% R (in general, it is preferable that thisreflectance of the video screen be minimized, such as by use ofanti-reflecting layers or elements, so that the reflectivity at thedisplay area of the EO mirror transflective element best matches, and isnot higher than, the reflectivity of the surrounding non-display areamirror reflector). A reflecting element 72 (such as a metal or metalcoated reflector) is disposed behind the two cold cathode fluorescentlight sources 81, 81′. A reflector housing or plastic housing 79protects and houses the video screen and associated backlighting etc.

When combined with a non-polarizing laminate (two-substrate)electrochromic window cell using a solid polymer matrix EC medium andwith ITO transparent conductors of about 12 to 15 ohms/square on thesecond and third surfaces that sandwich the EC medium, and with aVikuiti™ polarizing transflective film between the video display screenand the fourth surface of the EC cell, a display luminance or brightnessof about 907 Candelas/sq. meter was measured at the front (first)surface of the EC transflective mirror assembly [after about 5 minuteswarm-up; about 736 Candelas/sq. meter was measured at the front (first)surface of the EC transflective mirror assembly within 30 seconds ofpowering CCFL sources 81, 81′].

A visible light transmission spectral scan of the Vikuiti™ polarizingtransflective film used is shown in FIG. 9, indicating a visible lighttransmission of about 50% T. A visible light transmission spectral scanof the Vikuiti™ polarizing transflective film used combined with the ECcell used is shown in FIG. 10, indicating a visible light transmissionof about 40% T or thereabouts therethrough for their combination to makethe EC transflective mirror element (i.e., about 40% T transmittedthrough the transflective EC mirror element). The mirror reflectivity(per SAE J964a) at the display area of the EC mirror element (i.e. whereand with display device 70 was disposed behind the transflective ECelement) was about 46% R, and was about 42% R measured at thenon-display area. Another display device comprising a bank of LEDsinstead of use of two cold cathodes tubes was also tested.

In a construction otherwise such as shown in FIG. 7, thirty two (32)Nichia NESW008BT white light emitting LEDs were used as backlightingelement 78. With these LEDs, and using a similar EC cell and polarizingtransflective film as before, a display luminance (brightness) of about560 Candelas/sq. meter was achieved when viewed through the EC cell andthrough the polarizing transflective film. The Vikuiti™ and polarizingtransflective film used had a reflectivity (per SAE J964a) of about 55%R and, as indicated above, a transmission of about 50% in the visiblespectral region. Note that, optionally, the likes of a Vikuiti™anti-reflecting sheet or film can be used to reduce reflectance at thedisplay area or off the video display screen surface. And Vikuiti™all-polymeric specular mirror reflecting films (that are alsosignificantly light transmitting) can be used as a fourth surfacereflector for transmissive EC cells for use as transflective EC mirrorreflective elements for EC vehicular rearview mirrors.

Therefore, the interior mirror assembly of the present invention mayconsist of an electro-optic or electrochromic mirror utilizingtransparent conductors on the two interior surfaces (the second andthird surfaces) of the reflective element, with an electrochromic medium[such as a solid polymer matrix (SPM) material or the like] serving asthe electrically variable transmission EO medium. On the fourth surface,a reflective visible light transflecting/polarizing element or film maybe laminated or adhered or otherwise attached to the rear substrate(typically glass) by means of an optical grade adhesive, such as a filmadhesive or a liquid adhesive that cures, upon application, to a solid.Curing may be by UV curing and/or thermal curing and/or chemical curing.

The reflective visible light transflecting/polarizing element or filmhas a reflectivity that allows the end mirror product to maintain aminimum reflectance of at least about 40 percent, more preferably about50 percent or greater. The visible light transflecting/polarizingelement or film is disposed at the reflective element and displayelement so that the alignment angle or axis of the visible lighttransflecting/polarizing element or film corresponds or substantiallycorresponds with the alignment angle or axis of the Liquid CrystalDisplay (LCD) video display screen (or other) desired for use. Inaccordance with Malus's law, the transmission of the polarized lightthrough the visible light transflecting/polarizing element or film isreduced or impaired if the polarizing axes or angles are not aligned orsubstantially aligned. The two visible light transflecting/polarizingelement or films thus preferably align within about +/−10 degrees, morepreferably within about +/−5 degrees, more preferably within about +/−3degrees, and more preferably within about +/−1 degree of one another. Asshown in FIG. 3, the alignment angle or axis A of the visible lighttransflecting/polarizing element or film or films may be, for example,about 135 degrees from horizontal. However, other angles or axes may beutilized without affecting the scope of the present invention.

The reflective visible light transflecting/polarizing element or filmmay have a backing material that is either absorptive or, morepreferably, slightly reflective. An opaque material, such as a blackbacking tape, may be applied to the rear surface of the reflectiveelement to reduce or substantially eliminate the transparency of thefilm in the area or region where little or no transparency is desired.The mirror thus may have a greater reflectance in the viewing area ordisplay area directly in front of the display. Optionally, in order toproduce a more uniform appearing mirror, an anti-reflective coating orcoatings may be disposed at or applied to the front surface of thedisplay element, thus reducing or minimizing the amount of lightreflected back through the visible light transflecting/polarizingelement or film, or a material (such as a film or coating) may be placedbehind the reflective visible light transflecting/polarizing element orfilm that mimics or approximates the reflectance gain from the displaysurfaces.

Transparency or transmissivity of the reflective element is desired fora number of reasons, including, but not limited to the following:displaying information, light sensing for control of display luminancelevels, light sensing for control of variable reflectance mirror,sensing for vehicle safety features such as air bag active/in-active,and driver drowsiness alert and/or the like. The amount of transparencydesired, in the direction of polarization in the final mirror reflectorassembly, is preferably greater than about 60 percent, more preferablygreater than about 70 percent, and more preferably greater than about 80percent transmissivity or transparency at the reflective element.

The final display luminance (and especially for a TFT LCD displayelement showing video or full color video or still images), whenmeasured through the entire EO mirror element (comprising the EO elementbacked by the transflective reflective polarizing mirror reflector) ispreferably greater than about 300 candelas per meters squared (cd/m²),more preferably greater than about 500 cd/m², and more preferablygreater than about 1,000 cd/m² and most preferably greater than about2,000 cd/m². This is to help ensure that the driver can discern anyvideo image being displayed against the sunlight streaming in throughthe rear window and incident at the display area of the interior mirrorreflective element that will tend to wash-out the video image unless thevideo image is sufficiently bright. For such a TFT LCD display elementor other display types, the desired degree of luminance may be achievedby, but is not limited to, cold cathode fluorescent tubes, white LEDs,or white light generated through color mixing of red, green, and blueLEDs, or other suitable illumination sources or elements, located at theTFT LCD display element and rearward of the reflective element.

Because such a TFT LCD display element or screen may enhance thereflectivity of the reflective element at the display area, the displayarea may have a greater reflectance of light incident thereon ascompared to the rest of the viewing area of the reflective element.Thus, it may be desirable to overcoat the backing layer and/orpolarizing layer with a reflectance-boosting paint or material such as athin film metallic coating (in the viewing area of the reflectiveelement around the display area) to help match or substantially matchthe reflectivity of light incident at the display area of the reflectiveelement with the reflectivity of light incident at the rest of theviewing area of the reflective element.

In order to provide substantially uniform reflectivity andtransmissivity at the reflective element, it is important that the filmsor layers (such as the visible light transflecting/polarizing element orfilm and/or the backing layer or film) be applied or laid down with noor substantially no dirt or debris or the like between the films and/orbetween the film and the reflective element. Thus, it may be desirableto apply the film to the rear surface of the reflective element in aclean room environment, such as in preferably better than a class 10,000clean room environment, more preferably better than a class 1000 cleanroom environment, and more preferably better than a class 100 clean roomenvironment.

It is also highly desirable to limit or substantially preclude theformation of or entrapment of air bubbles between the film and thereflective element as it is applied to the reflective element. The filmthus may be ironed (such by roller-ironing) or pressed to remove orreduce imperfections, preferably applying heat as well as pressure andmost preferably, doing so in an evacuated chamber free or atmospherewhere air has been at least partially evacuated while laminating.Optionally, and desirably, the film may be applied via a vacuum assistedlamination/application, whereby any air between the film and thereflective element is drawn out or evacuated via a vacuum source as thefilm is applied to the reflective element.

For example, the EO cell or element and a sheet (or an interior mirrorshaped cut-out) of the visible light transflecting/polarizing element orfilm [such as Vikuiti™ Dual Brightness Enhancement Film-Polarizer(DBEF-P2) film available from 3M that is a multi-layer reflectivepolarizer designed to be laminated to the to bottom glass of an LCDmodule; through polarization recycling the Vikuiti™ DBEF-P2 reflects theP2 light back into the backlight where it is scrambled into P1 and P2,and whose product, uses thereof, or its manufacture may be covered byone or more of the following U.S. Pat. Nos. 5,094,788; 5,122,905;5,122,906; 5,269,995; 5,389,324; 5,594,830; 5,808,794; 5,825,542;5,828,488; 5,867,316; 5,872,653; 5,882,774; 5,962,114; 5,965,247;5,976,424; 6,018,419; 6,025,897; 6,057,961; 6,080,467; 6,088,067;6,088,159; 6,101,032; 6,117,530; 6,124,971; 6,141,149; 6,157,490;6,296,927; 6,307,676; 6,352,761; 6,449,092; 6,449,093; 6,498,683;6,574,045; 6,583,930; 6,613,421; 6,630,970; 6,635,337 and 6,641,883, theentire disclosures of which are hereby incorporated herein by referencein their entireties] may be introduced into a chamber, air can beevacuated using a vacuum pump or the like, the EO cell may be placed inthe evacuated dust-free chamber and the visible lighttransflecting/polarizing film may be applied such as is illustrated inFIGS. 5A and 5B. As seen in FIG. 5A, an electro-optic cell 40 is placedin a chamber 45 and is laid onto a heater block 42 with its fourthsurface 43 upwards. A sheet (or mirror-shaped cut-out) or film 44 ofVikuiti™ DBEF-P2 or similar visible light transflecting/polarizingelement or film is initially spaced from electro-optic cell 40. A rolleror roller means 48 (such as a heated roller) is also provided. As aninitial step, and preferably, chamber 45 is at least partially evacuatedand preferably is substantially evacuated of air (and so obviatingentrapment of air bubbles when laminating the transflective polarizingfilm 44 to glass surface 43) such as by a means of a vacuum pump. Thisalso helps remove any lint or dust that might be present and that couldget entrapped during lamination. Next, heater block 42 is heated (bymeans of, for example, electrically-operated heating rods embeddedtherein) so as to heat the electro-optic cell 40 to, for example, atemperature in the range from about 60 degrees Celsius to about 150degrees Celsius, or higher depending on the nature of the electro-opticmedium (such as an electrochromic medium) in cell 40 (if such is alreadyestablished therein). Also, and preferably, roller 48 may also be heatedso as to heat the portion of film 44 it is contacting (the temperaturechosen depending on the type of film used and on any adhesive layerspresent).

Next, and beginning at an outer edge of electro-optic cell 40, roller 48is mechanically moved to intimately press film 44 (under pressure of atleast about 2 psi, more preferably at least about 5 psi and mostpreferably at least about 10 psi) to contact with surface 43 ofelectro-optic (such as electrochromic) cell 40. While maintaining heatand pressure, roller 48 is mechanically moved from its initial edgecontact to cell 40 across the surface of cell 40 to intimatelybond/laminate the film 44 to cell 40 (FIG. 5B illustrates this inprogress). The temperatures, roller speeds and pressures are chosen toiron out, if necessary, any optical imperfections, distortions orwrinkles or the like and to produce a distortion-free,specularly-reflecting mating of film 44 to surface 43. Onceroller-assisted lamination is completed, air or nitrogen or the like isreintroduced into chamber 45 to re-pressurize the chamber back toatmospheric pressure, and the electro-optic or electrochromic mirrorreflector element is removed from the chamber, allowed to cool ifnecessary, and any excess film 44 is trimmed away. Other laminationtechniques as known in the liquid crystal cell manufacturing arts canalso be used within the scope of the present invention. It may be usefulto use a fluid or semi-fluid adhesive that can fill-in and preferablyoptically match any imperfections (such as imperfections in glasssurface 43 and/or in film 44) between film 44 and glass surface 43during lamination of film 44 thereto (and once film 44 is in place, thenallowing this fluid adhesive or optical matching layer to cure, such asby chemical or thermal or radiation-assisted curing, to a solid,non-fluid form), and UV sources and/or thermal radiant heaters such asIR lamps or the like may be provided within chamber 45 to UV and/orthermally cure any ultra violet light or thermally curable adhesives ormaterials used. Note also that electrostatic charge reduction/mitigationmeans or methods, such as ionizing sources and the like, can be usedduring lamination to avoid attracting dust or lint or the like to thesurfaces being laminated.

Optionally, the visible light transflecting/polarizing element or filmmay be applied as a large sheet (i.e. a sheet that is larger than thecross dimensions of the rear surface of the electro-optic element) thatis laid over the substrate shape. The sheet or film may be heat shrunkor heat applied around the electro-optic element with vacuum means usedto draw or evacuate the air from between the film and the rear surfaceof the electro-optic element, and then, once conforming to the glasssurface and cooled, the excess sheet or film material may be trimmedaway from the mirror element so that the film is applied at and over therear surface of the electro-optical element with substantially no airentrapped between the film and the electro-optic element and makingintimate and distortion-free contact thereto. Optionally, the visiblelight transflecting/polarizing element or film may be applied to therear surface of the electro-optic element at an elevated temperature soas to make the polymeric film more compliant so as to more readilyconform to the substrate shape (depending on the film used, temperaturesup to about 150 degrees Celsius or more can be contemplated; and withthe electro-optical element and/or the film being applied being heated).Optionally, the film may be applied via an affirmative pressure device,such as a roller or the like, so as to force any air bubbles or pocketsout from between the film and the electro-optic element. For example,the film may be heated, such as to about between about 60 degreesCelsius to about 125 degrees Celsius or thereabouts or higher, and thenmay be rolled or ironed or pressed onto the rear surface of the rearsubstrate of the electro-optical element, optionally with a vacuum meanssuch as vacuum lamination being used to aid avoidance of entrapped airand/or ensure conformity to the surface, such as described above.Optionally, the film and/or the glass surface to which it is beingapplied can be provided with an optically-matching (refractive index inthe about 1.48 to about 1.55 range) pressure sensitive or liquidadhesive. Preferably, this index matching medium is fluid during theapplication of the film to the glass surface so as to flow into and thusfill/optically match and imperfections in the glass surface and/or thefilm being applied thereto.

The rearview mirror assembly may comprise an electro-optic orelectrochromic reflective element or cell, such as an electrochromicmirror assembly and electrochromic reflective element utilizingprinciples disclosed in commonly assigned U.S. Pat. Nos. 6,690,268;5,140,455; 5,151,816; 6,178,034; 6,154,306; 6,002,544; 5,567,360;5,525,264; 5,610,756; 5,406,414; 5,253,109; 5,076,673; 5,073,012;5,117,346; 5,724,187; 5,668,663; 5,910,854; 5,142,407; 4,824,221;5,818,636; 6,166,847; 6,111,685; 6,392,783; 6,710,906; 6,798,556;6,554,843; 6,420,036 and/or 4,712,879, and/or U.S. patent applicationSer. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381;and/or Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S. Pat. No.7,255,451, and/or International Pat. Publication Nos. WO 2004/098953,published Nov. 18, 2004; WO 2004/042457, published May 21, 2004; WO2003/084780, published Oct. 16, 2003; and/or WO 2004/026633, publishedApr. 1, 2004, which are all hereby incorporated herein by reference intheir entireties, and/or as disclosed in the following publications: N.R. Lynam, “Electrochromic Automotive Day/Night Mirrors”, SAE TechnicalPaper Series 870636 (1987); N. R. Lynam, “Smart Windows forAutomobiles”, SAE Technical Paper Series 900419 (1990); N. R. Lynam andA. Agrawal, “Automotive Applications of Chromogenic Materials”, LargeArea Chromogenics: Materials and Devices for Transmittance Control, C.M. Lampert and C. G. Granquist, EDS., Optical Engineering Press, Wash.(1990), which are hereby incorporated herein by reference in theirentireties.

Optionally, use of an elemental semiconductor mirror, such as a siliconmetal mirror, such as disclosed in U.S. Pat. Nos. 6,286,965; 6,196,688;5,535,056; 5,751,489; and 6,065,840, and/or in U.S. patent applicationSer. No. 10/993,302, filed Nov. 19, 2004, now U.S. Pat. No. 7,338,177,which are all hereby incorporated herein by reference in theirentireties, can be advantageous because such elemental semiconductormirrors (such as can be formed by depositing a thin film of silicon) canbe greater than 50 percent reflecting in the photopic (SAE J964ameasured), while being also substantially transmitting of light (up to20 percent or even more). Such silicon mirrors also have the advantageof being able to be deposited onto a flat glass substrate and to be bentinto a curved (such as a convex or aspheric) curvature, which is alsoadvantageous since many passenger-side exterior rearview mirrors arebent or curved.

The transparent conductive layer or layers at the second and thirdsurfaces of the reflective element may comprise any suitable transparentconductive coatings or layers, such as an indium tin oxide (ITO) ordoped (antimony or fluorine doped) tin oxide or doped zinc oxide (suchas aluminum-doped zinc oxide) or an ITO/thin Ag/ITO stack or an ITO/thinAl/ITO stack or a thin (preferably, less than about 200 angstroms inphysical thickness; more preferably less than about 150 angstroms thick;most preferably less than about 125 angstroms thick; and greater thanabout 75 angstroms thick, more preferably greater than about 85angstroms thick and most preferably greater than about 100 angstromsthick) coating of silver (or a silver alloy) sandwiched between ITO ordoped zinc oxide layers or a thin coating of aluminum (or an aluminumalloy) sandwiched between ITO or doped zinc oxide layers or a thincoating of platinum or palladium (or an alloy thereof) sandwichedbetween ITO or doped zinc oxide layers or a thin coating of ruthenium(or a ruthenium alloy) sandwiched between ITO or doped zinc oxidelayers, or such as the conductive layers described in U.S. Pat. Nos.6,690,268; 5,668,663; 5,142,406; 5,442,478 and 5,724,187, and/or in U.S.patent application Ser. No. 10/054,633, filed Jan. 22, 2002, now U.S.Pat. No. 7,195,381; Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S.Pat. No. 7,255,451; Ser. No. 10/528,269, filed Mar. 17, 2005, now U.S.Pat. No. 7,274,501; Ser. No. 10/533,762, filed May 4, 2005, now U.S.Pat. No. 7,184,190; Ser. No. 10/538,724, filed Jun. 13, 2005 andpublished Mar. 9, 2006 as U.S. Publication No. US-2006-0050018; Ser. No.11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 as U.S.Publication No. US-2006-0061008; Ser. No. 10/993,302, filed Nov. 19,2004, now U.S. Pat. No. 7,338,177; and/or Ser. No. 11/284,543, filedNov. 22, 2005, now U.S. Pat. No. 7,370,983, and/or in PCT ApplicationNo. PCT/US03/29776, filed Sep. 19, 2003 and published Apr. 1, 2004 asInternational Publication No. WO 2004/026633; and/or PCT Application No.PCT/US03/35381, filed Nov. 5, 2003 and published May 21, 2004 asInternational Publication No. WO 2004/042457, which are herebyincorporated herein by reference in their entireties. Note thatdouble-silver stacks (as such term is commonly known and used in theheat mirror-coated art) may be used as a transparent conductor layer.Transparent conductor layers useful in the mirror element of the presentinvention thus may comprise conductive material such as tin oxide (SnO₂)doped with antimony or fluorine, indium oxide, indium oxide and tin (In₂O₃ Sn) (preferably 5-15 percent Sn), zinc oxide (ZnO), zinc oxyfluoride,zinc oxide and indium (ZnO:In), zinc oxide and aluminum (ZnO:Al),cadmium stannate (Cd₂ SnO₄), cadmium stannite (CdSnO₃), cadmium oxide(CdO), copper sulfide (Cu₂ S), titanium nitride (TiN), or titaniumoxynitride (TiOx N1-x) to provide electrical contact to theelectrochromic medium and/or for other layers/elements useful in themirror element of the present invention.

Although shown and described as an electro-optic or electrochromicelectro-optic element assembly or cell, the reflective element maycomprise a single substrate (and thus only having a first surface and asecond surface) with a reflective coating at its rear (second) surface,without affecting the scope of the present invention. For example, themirror assembly may comprise a prismatic mirror element or other mirrorelement having a single substrate reflective element, such as a mirrorassembly utilizing aspects described in U.S. Pat. Nos. 6,318,870;6,598,980; 5,327,288; 4,948,242; 4,826,289; 4,436,371; and 4,435,042;and PCT Application No. PCT/US04/015424, filed May 18, 2004 andpublished Dec. 2, 2004 as International Publication No. WO 2004/103772;and U.S. patent application Ser. No. 10/933,842, filed Sep. 3, 2004, nowU.S. Pat. No. 7,249,860, which are all hereby incorporated herein byreference in their entireties. Optionally, the reflective element maycomprise a conventional prismatic or flat reflective element or prism,or may comprise a prismatic or flat reflective element of the typesdescribed in PCT Application No. PCT/US03/29776, filed Sep. 19, 2003 andpublished Apr. 1, 2004 as International Publication No. WO 2004/026633;U.S. patent application Ser. No. 10/709,434, filed May 5, 2004, now U.S.Pat. No. 7,420,756; Ser. No. 10/528,269, filed Mar. 17, 2005, now U.S.Pat. No. 7,274,501; Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S.Pat. No. 7,249,860; Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S.Pat. No. 7,255,451; and/or Ser. No. 10/993,302, filed Nov. 19, 2004, nowU.S. Pat. No. 7,338,177, and/or PCT Application No. PCT/US2004/015424,filed May 18, 2004 and published Dec. 2, 2004 as InternationalPublication No. WO 2004/103772, which are all hereby incorporated hereinby reference in their entireties, without affecting the scope of thepresent invention. A variety of mirror accessories and constructions areknown in the art, such as those disclosed in U.S. Pat. Nos. 5,555,136;5,582,383; 5,680,263; 5,984,482; 6,227,675; 6,229,319 and 6,315,421(which are all hereby incorporated herein by reference in theirentireties), that can benefit from the present invention.

Optionally, the mirror assembly may include one or more displays, suchas the types disclosed in U.S. Pat. Nos. 5,530,240 and/or 6,329,925,which are hereby incorporated herein by reference in their entireties,and/or display-on-demand or transflective type displays, such as thetypes disclosed in U.S. Pat. Nos. 6,690,268; 5,668,663 and/or 5,724,187,and/or in U.S. patent application Ser. No. 10/054,633, filed Jan. 22,2002, now U.S. Pat. No. 7,195,381; Ser. No. 10/528,269, filed Mar. 17,2005, now U.S. Pat. No. 7,274,501; Ser. No. 10/533,762, filed May 4,2005, now U.S. Pat. No. 7,184,190; Ser. No. 10/538,724, filed Jun. 13,2005 and published Mar. 9, 2006 as U.S. Publication No. US-2006-0050018;Ser. No. 11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 asU.S. Publication No. US-2006-0061008; Ser. No. 10/993,302, filed Nov.19, 2004, now U.S. Pat. No. 7,338,177; Ser. No. 11/284,543, filed Nov.22, 2005, now U.S. Pat. No. 7,370,983; and/or Ser. No. 11/021,065, filedDec. 23, 2004, now U.S. Pat. No. 7,255,451; and/or PCT Application No.PCT/US03/29776, filed Sep. 9, 2003 and published Apr. 1, 2004 asInternational Publication No. WO 2004/026633; and/or PCT Application No.PCT/US03/35381, filed Nov. 5, 2003 and published May 21, 2004 asInternational Publication No. WO 2004/042457; and/or U.S. provisionalapplications, Ser. No. 60/630,061, filed Nov. 22, 2004; Ser. No.60/667,048, filed Mar. 31, 2005; Ser. No. 60/629,926, filed Nov. 22,2004; Ser. No. 60/531,838, filed Dec. 23, 2003; Ser. No. 60/553,842,filed Mar. 17, 2004; Ser. No. 60/563,342, filed Apr. 19, 2004; Ser. No.60/681,250, filed May 16, 2005; Ser. No. 60/690,400, filed Jun. 14,2005; Ser. No. 60/695,149, filed Jun. 29, 2005; Ser. No. 60/717,093,filed Sep. 14, 2005; and/or Ser. No. 60/730,334, filed Oct. 26, 2005,and/or PCT Application No. PCT/US03/40611, filed Dec. 19, 2003 andpublished Jul. 15, 2004 as International Publication No. WO 2004/058540,which are all hereby incorporated herein by reference in theirentireties, or may include or incorporate video displays or the like,such as the types described in PCT Application No. PCT/US03/40611, filedDec. 19, 2003 and published Jul. 15, 2004 as International PublicationNo. WO 2004/058540, U.S. patent application Ser. No. 11/284,543, filedNov. 22, 2005, now U.S. Pat. No. 7,370,983; and/or Ser. No. 10/538,724,filed Jun. 13, 2005 and published Mar. 9, 2006 as U.S. Publication No.US-2006-0050018, and/or U.S. provisional applications, Ser. No.60/630,061, filed Nov. 22, 2004; and Ser. No. 60/667,048, filed Mar. 31,2005, which are hereby incorporated herein by reference in theirentireties.

Optionally, the mirror assembly may support one or more otheraccessories or features, such as one or more electrical or electronicdevices or accessories. For example, illumination sources or lights,such as map reading lights or one or more other lights or illuminationsources, such as illumination sources of the types disclosed in U.S.Pat. Nos. 6,690,268; 5,938,321; 5,813,745; 5,820,245; 5,673,994;5,649,756; 5,178,448; 5,671,996; 4,646,210; 4,733,336; 4,807,096;6,042,253; 6,971,775 and/or 5,669,698, and/or U.S. patent applicationSer. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381;and/or Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No.7,249,860, which are hereby incorporated herein by reference in theirentireties, may be included in the mirror assembly. The illuminationsources and/or the circuit board may be connected to one or more buttonsor inputs for activating and deactivating the illumination sources.Optionally, the mirror assembly may also or otherwise include otheraccessories, such as microphones, such as analog microphones or digitalmicrophones or the like, such as microphones of the types disclosed inU.S. Pat. Nos. 6,243,003; 6,278,377; and/or 6,420,975, and/or in U.S.patent application Ser. No. 10/529,715, filed Mar. 30, 2005, publishedon May 25, 2006 as U.S. Pat. Publication No. US-2006-0109996, now U.S.Pat. No. 7,657,052; and/or in PCT Application No. PCT/US03/308877, filedOct. 1, 2003 and published Apr. 15, 2004 as International PublicationNo. WO 2004/032568. Optionally, the mirror assembly may also orotherwise include other accessories, such as a telematics system,speakers, antennas, including global positioning system (GPS) orcellular phone antennas, such as an ONSTAR® system as found in GeneralMotors vehicles and such as described in U.S. Pat. Nos. 4,862,594;4,937,945; 5,131,154; 5,255,442; 5,632,092; 5,798,688; 5,971,552;5,924,212; 6,243,003; 6,278,377; and 6,420,975; 6,477,464; and/or6,678,614; and/or U.S. patent application Ser. No. 10/456,599, filedJun. 6, 2003, now U.S. Pat. No. 7,004,593; Ser. No. 10/645,762, filedAug. 20, 2003, now U.S. Pat. No. 7,167,796; Ser. No. 10/964,512, filedOct. 13, 2004, now U.S. Pat. No. 7,308,341; Ser. No. 10/422,378, filedApr. 24, 2003, now U.S. Pat. No. 6,946,978; and Ser. No. 10/529,715,filed Mar. 30, 2005, published on May 25, 2006 as U.S. Pat. PublicationNo. US-2006-0109996, now U.S. Pat. No. 7,657,052; and/or PCT ApplicationNo. PCT/US03/40611, filed Dec. 19, 2003 and published Jul. 15, 2004 asInternational Publication No. WO 2004/058540, and/or PCT Application No.PCT/US03/308877, filed Oct. 1, 2003 and published Apr. 15, 2004 asInternational Publication No. WO 2004/032568, a communication module,such as disclosed in U.S. Pat. No. 5,798,688, a voice recorder, a blindspot detection and/or indication system, such as disclosed in U.S. Pat.Nos. 5,929,786 and/or 5,786,772, and/or U.S. patent application Ser. No.10/427,051, filed Apr. 30, 2003, now U.S. Pat. No. 7,038,577; Ser. No.11/315,675, filed Dec. 22, 2005, now U.S. Pat. No. 7,720,580; and Ser.No. 10/209,173, filed Jul. 31, 2002, now U.S. Pat. No. 6,882,287; and/orU.S. provisional applications, Ser. No. 60/638,687, filed Dec. 23, 2004;Ser. No. 60/784,570, filed Mar. 22, 2006; and/or Ser. No. 60/696,953,filed Jul. 6, 2006, and/or PCT Application No. PCT/US2006/026148, filedJul. 5, 2006 and published Jan. 11, 2007 as International PublicationNo. WO 2007/005942, transmitters and/or receivers, such as for a garagedoor opener or a vehicle door unlocking system or the like (such as aremote keyless entry system), a digital network, such as described inU.S. Pat. No. 5,798,575, a compass indicator or display and/or atemperature indicator or display, such as described in U.S. Pat. No.7,004,593; and/or U.S. patent application Ser. No. 11/305,637, filedDec. 16, 2005, now U.S. Pat. No. 7,329,013, a high/low headlampcontroller, such as a camera-based headlamp control, such as disclosedin U.S. Pat. Nos. 5,796,094 and/or 5,715,093, a memory mirror system,such as disclosed in U.S. Pat. No. 5,796,176, a hands-free phoneattachment, an imaging system or components or circuitry or displaythereof, such as an imaging and/or display system of the types describedin U.S. Pat. Nos. 6,690,268 and 6,847,487; and/or U.S. provisionalapplications, Ser. No. 60/614,644, filed Sep. 30, 2004; Ser. No.60/618,686, filed Oct. 14, 2004; Ser. No. 60/628,709, filed Nov. 17,2004; Ser. No. 60/644,903, filed Jan. 11, 2005; Ser. No. 60/667,049,filed Mar. 31, 2005; and/or U.S. patent application Ser. No. 11/105,757,filed Apr. 14, 2005, now U.S. Pat. No. 7,526,103; Ser. No. 11/239,980,filed Sep. 30, 2005, now U.S. Pat. No. 7,881,496; and/or Ser. No.11/334,139, filed Jan. 18, 2006, now U.S. Pat. No. 7,400,435, a slideout or extendable/retractable video device or module, such as describedin U.S. patent application Ser. No. 10/538,724, filed Jun. 13, 2005 andpublished Mar. 9, 2006 as U.S. Publication No. US-2006-0050018; and/orSer. No. 11/284,543, filed Nov. 22, 2005, now U.S. Pat. No. 7,370,983,U.S. provisional applications, Ser. No. 60/630,061, filed Nov. 22, 2004;and/or Ser. No. 60/667,048, filed Mar. 31, 2005; and/or PCT ApplicationNo. PCT/US03/40611, filed Dec. 19, 2003 and published Jul. 15, 2004 asInternational Publication No. WO 2004/058540, a video device forinternal cabin surveillance (such as for sleep detection or driverdrowsiness detection or the like) and/or video telephone function, suchas disclosed in U.S. Pat. Nos. 5,760,962 and/or 5,877,897, an occupantdetection system (such as the types described in PCT Application No.PCT/US2005/042504, filed Nov. 22, 2005 and published Jun. 1, 2006 asInternational Publication No. WO 2006/058098, a heating element,particularly for an exterior mirror application, such as the typesdescribed in U.S. patent application Ser. No. 11/334,139, filed Jan. 18,2006, now U.S. Pat. No. 7,400,435, a remote keyless entry receiver, aseat occupancy detector, a remote starter control, a yaw sensor, aclock, a carbon monoxide detector, status displays, such as displaysthat display a status of a door of the vehicle, a transmission selection(4 wd/2 wd or traction control (TCS) or the like), an antilock brakingsystem, a road condition (that may warn the driver of icy roadconditions) and/or the like, a trip computer, a tire pressure monitoringsystem (TPMS) receiver (such as described in U.S. Pat. Nos. 6,124,647;6,294,989; 6,445,287; 6,472,979 and/or 6,731,205; and/or U.S. patentapplication Ser. No. 11/232,324, filed Sep. 21, 2005, now U.S. Pat. No.7,423,522; and/or U.S. provisional application, Ser. No. 60/611,796,filed Sep. 21, 2004), and/or an ONSTAR® system and/or any otheraccessory or circuitry or the like (with all of the above-referencedpatents and PCT and U.S. patent applications being commonly assigned,and with the disclosures of the referenced patents and patentapplications being hereby incorporated herein by reference in theirentireties).

Optionally, the mirror assembly may accommodate other accessories orcircuitry or the like as well, such as a rain sensor or imaging deviceor the like. For example, the mirror assembly may include a mountingportion (such as the types described in U.S. patent application Ser. No.11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 as U.S.Publication No. US-2006-0061008; and/or U.S. provisional applications,Ser. No. 60/692,113, filed Jun. 20, 2005; Ser. No. 60/677,990, filed May5, 2005; Ser. No. 60/653,787, filed Feb. 17, 2005; Ser. No. 60/642,227,filed Jan. 7, 2005; Ser. No. 60/638,250, filed Dec. 21, 2004; Ser. No.60/624,091, filed Nov. 1, 2004, and Ser. No. 60/609,642, filed Sep. 14,2004, which are all hereby incorporated herein by reference in theirentireties), and may include a rain sensor or the like and may positionthe rain sensor against the windshield, such as described in U.S. Pat.Nos. 6,250,148; 6,341,523; and 6,824,281, and in U.S. patent applicationSer. No. 10/023,162, filed Dec. 17, 2001, now U.S. Pat. No. 6,516,664;Ser. No. 10/348,514, filed Jan. 21, 2003, now U.S. Pat. No. 6,968,736;Ser. No. 10/958,087, filed Oct. 4, 2004, now U.S. Pat. No. 7,188,963;and/or Ser. No. 11/201,661, filed Aug. 11, 2005, now U.S. Pat. No.7,480,149, which are all hereby incorporated herein by reference intheir entireties. Optionally, the mirror assembly may include an imagingdevice, such as an imaging array sensor for imaging systems of the typesdescribed in U.S. Pat. Nos. 6,946,978; 6,757,109; 6,717,610; 6,396,397;6,201,642; 6,353,392; 6,313,454; 6,396,397; 5,550,677; 5,670,935;5,796,094; 5,877,897; 6,097,023 and 6,498,620, and U.S. patentapplication Ser. No. 09/441,341, filed Nov. 16, 1999, now U.S. Pat. No.7,339,149, and Ser. No. 10/427,051, filed Apr. 30, 2003, now U.S. Pat.No. 7,038,577; and/or PCT application No. PCT/US2006/041709, filed Oct.27, 2006 and published May 10, 2007 as International Publication No. WO2007/053404; and/or U.S. provisional applications, Ser. No. 60/731,183,filed Oct. 28, 2005; and/or Ser. No. 60/765,797, filed Feb. 7, 2006,which are all hereby incorporated herein by reference in theirentireties.

Optionally, the mirror assembly may be utilized with a video slide-outmirror, such as the types described in U.S. patent application Ser. No.11/284,543, filed Nov. 22, 2005, now U.S. Pat. No. 7,370,983; and/orSer. No. 10/538,724, filed Jun. 13, 2005 and published Mar. 9, 2006 asU.S. Publication No. US-2006-0050018; PCT Application No.PCT/US03/40611, filed Dec. 19, 2003 and published Jul. 15, 2004 asInternational Publication No. WO 2004/058540, and/or U.S. provisionalapplications, Ser. No. 60/630,061, filed Nov. 22, 2004; and Ser. No.60/667,048, filed Mar. 31, 2005, which are hereby incorporated herein byreference in their entireties. Further, when such a vehicle equippedwith such a video mirror is also equipped with a side viewing or frontviewing or rear viewing sensor vision system (such as by utilizing aradar sensor or an ultrasonic sensor or a camera sensor (such asdescribed in U.S. patent application Ser. No. 11/239,980, filed Sep. 30,2005, now U.S. Pat. No. 7,881,496; and/or Ser. No. 11/315,675, filedDec. 22, 2005, now U.S. Pat. No. 7,720,580, and/or U.S. provisionalapplications, Ser. No. 60/628,709, filed Nov. 17, 2004; Ser. No.60/614,644, filed Sep. 30, 2004; Ser. No. 60/618,686, filed Oct. 14,2004; and/or Ser. No. 60/638,687, filed Dec. 23, 2004, which are herebyincorporated herein by reference in their entireties) to monitor an areaadjacent the vehicle), the video screen may automatically extend whensuch a sensor system detects the presence of an obstacle and/or a humanadjacent to the vehicle. Also, the video display screen may extend inconjunction with a trailer-hitch monitoring system (such as the typesdescribed in U.S. patent application Ser. No. 10/418,486, filed Apr. 18,2003, now U.S. Pat. No. 7,005,974, which is hereby incorporated hereinby reference in its entirety) and icons and/or indicia and/orinstructions may be created on the video image displayed on the extendedvideo screen of the video mirror to assist or guide the driver to hitcha trailer to the trailer hitch of the vehicle.

Optionally, the mirror assembly may include one or more user actuatableinputs or input devices or human machine interfaces. For example, theinputs or user interfaces may include buttons, such as are described inU.S. Pat. No. 6,501,387, and/or U.S. patent application Ser. No.11/451,639, filed Jun. 13, 2006, now U.S. Pat. No. 7,527,403; and/orU.S. provisional applications, Ser. No. 60/690,401, filed Jun. 14, 2005;Ser. No. 60/719,482, filed Sep. 22, 2005; and/or and Ser. No.60/749,423, filed Dec. 12, 2005, which are hereby incorporated herein byreference in their entireties, or that include touch/proximity sensorssuch as are disclosed in U.S. Pat. Nos. 6,001,486; 6,310,611; 6,320,282and 6,627,918, and U.S. patent application Ser. No. 09/817,874, filedMar. 26, 2001, now U.S. Pat. No. 7,224,324, and PCT Application No.PCT/US03/40611, filed Dec. 19, 2003 and published Jul. 15, 2004 asInternational Publication No. WO 2004/058540, which are herebyincorporated herein by reference in their entireties, or that includeother types of buttons or switches, such as those described in U.S.patent application Ser. No. 11/029,695, filed Jan. 5, 2005, now U.S.Pat. No. 7,253,723; and/or U.S. provisional applications, Ser. No.60/556,259, filed Mar. 25, 2004; Ser. No. 60/553,517, filed Mar. 16,2004; and Ser. No. 60/535,559, filed Jan. 9, 2004; and/or PCTApplication No. PCT/US2004/015424, filed May 18, 2004 and published Dec.2, 2004 as International Publication No. WO 2004/103772, which arehereby incorporated herein by reference in their entireties, or thatinclude fabric-made position detectors, such as are disclosed in U.S.Pat. Nos. 6,504,531; 6,501,465; 6,492,980; 6,452,479; 6,437,258 and6,369,804, which are hereby incorporated herein by reference in theirentireties. The manual inputs or user actuatable inputs or actuators maycontrol or adjust or activate/deactivate one or more accessories orelements or features. For touch sensitive inputs or applications orswitches, the mirror assembly or accessory module or input may, whenactivated, provide a positive feedback (such as activation of anillumination source or the like, or such as via an audible signal, suchas a chime or the like, or a tactile or haptic signal, or a rumbledevice or signal or the like) to the user so that the user is made awarethat the input was successfully activated.

Although preferably realized using a unitary combined visible lighttransflecting/polarizing element, the present invention encompasses useof a separate light reflector element and separate polarizing element.Also, while linearly polarization is preferred, use of otherpolarization forms, such as circular polarization and ellipticalpolarization, can be envisaged without affecting the scope of thepresent invention.

Also note that display washout may be mitigated or reduced by use oflight control films such as by use of Vikuiti™ Light Control films from3M of Minneapolis (whose construction is disclosed such as in U.S. Pat.Nos. 4,764,410; 4,766,023 and 5,254,388, which are hereby incorporatedherein by reference in their entireties). Since the interior rearviewmirror element (and any video screen attached to the rear surfacethereof) is typically canted by the driver at an angle of about 22degrees or so to the longitudinal axis of the vehicle and since sunlightpasses through the rear window of the vehicle at an angle generallyparallel with the longitudinal axis of the vehicle, a light control filmcomprising micro louvers (such as at an about 22 degree angle) canted orslanted towards the driver can be used at the display area so that thesunlight and the like passing through a rear window of the vehicle andaxial with the longitudinal axis is blocked or reflected away from thedriver's eyes, but light emitted from the display device to the rear ofthe mirror element pass through the micro louvers to be seen by thedriver. Also, Vikuiti™ Image Directing Film (IDF II), which is atransparent optical composite that redirects the image created by adisplay to the optimum viewing angle (such as disclosed in U.S. Pat. No.5,303,322, which is hereby incorporated herein by reference in itsentirety), can be used to assist prevention of video image washout bydaylight for through-the-mirror reflector video displays used ininterior rearview mirrors. Vikuiti™ Image Directing Film (IDF) is apolymer film comprising an acrylic prismatic structure overlaid on apolyester structure and with the prismatic structure designed so thatany optical image passing through will be offset, or redirected, by adetermined angle, such as, for example, 20 degrees. Use can also be madeof Vikuiti BEF III-10T film that provides about a 37 percent increase inon-axis brightness for direct-light systems and that, when combined withVikuiti DBEF-D400 (or D550) film, on-axis brightness can be increased byup to 68 percent or thereabouts. Additionally, combining Vikuiti BEFIII-10T film with Vikuiti DBEF film may beneficially improve contrast incertain EO mirror constructions. Vikuiti BEF III-10T film also improvesuniformity by hiding direct-light system cold cathode fluorescentlighting bulbs. And beneficial use, in certain constructions, may befound for Vikuiti™ Rounded Brightness Enhancement Film (RBEF) thatfeatures a micro-replicated prismatic structure with rounded peaks thatcontrol the exit angle of the light, and that helps maximize theefficiency of backlighting while maintaining a wide viewing angle with asoft cut-off. Also, if a Vikuiti™ BEF-RP multilayered reflectivepolarizer is used with an EO cell, a second film or sheet of Vikuiti™Thin BEF film may be used to gain greater display brightness, preferablywith its grooves at 90 degrees away the grooves direction of theVikuiti™ BEF-RP film. Other constructions may be implemented withoutaffecting the scope of the present invention.

Also, the third and/or fourth surface of the electro-optical cell can becoated with a significantly light reflecting/significantly lighttransmitting multi-layer thin film stack. For example, and starting froma glass surface, the stack of layers may include the following (with theapproximate thickness of the layers set forth below in nanometers):

Glass Surface SiO₂ 8.63 TiO₂ 22.98 SiO₂ 339.47 TiO₂ 19.59 SiO₂ 54.96TiO₂ 48.18 SiO₂ 86.19 TiO₂ 51.85 SiO₂ 84.99 TiO₂ 79.75 SiO₂ 174.07 ITO21.26

A glass substrate coated with such a 12-layer stack will have opticalperformance as shown in FIG. 6 (with air being the exit medium). Visiblelight transmission of light therethrough is about 32% T and visiblelight reflectivity of light incident thereon is about 67% R. Note thatthe outermost layer is ITO, which is a transparent conductor. If such amulti-layer broadband reflector/transmitter transflective stack (havingspectral neutrality in both reflectance and in transmission of visiblelight across the visible light spectrum) is to be used as third surfacereflector in an electro-optical (such as an EC cell), it is importantthat its outermost layer be electrically conducting as this is the layerthat contacts the EC medium in the interpane cavity of the EO cell.Other designs for a broadband reflector/transmitter transflective stackwill suggest themselves to those skilled in the optical filter designarts; in general, it is desirable to have at least 5 layers, and morepreferable to have at least 8 layers and most preferable to have atleast 10 layers in the stack design. For economy of coating, it ispreferable that these layers be mostly of repeating/alternatingmaterials (such as SiO₂ and TiO₂). If the outermost layer is notelectrically conducting, such a broadband reflector/transmittertransflective stack can be used on the fourth surface of the EO cellwith an ITO transparent conducting coating or layer or the like on thethird surface of the EO cell (such as an EC cell) or device.

Also, use of a bank or matrix or plurality of high power LEDs can beused for backlighting the video display behind a transflectiveelectrochromic or other EO mirror reflective element. Heatreduction/mitigation methods such as heat sinks, use of DC-to-DCconverters and series electrical connection of a string of individualLEDs (so that their combined series voltage drop is close to the 12Vnominal of the vehicle battery/ignition system) may be used. Beneficialuse can be made of the disclosure and teachings of U.S. patentapplication Ser. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No.7,195,381, which is hereby incorporated herein by reference in itsentirety. For example, a bank of 4 or 8 or even 12 or more Luxeon® K2high-power LEDS can be used as the backlighting source. Such aresupplied by LumiLeds Lighting U.S. LLC, and are rated to provide greaterthan about 140 lumens in 6,599 K white. Use of DC-to-DC conversioncoupled with heat sinking and/or series electrical connection ofmultiple individual LEDs can help manage heat loading within theinterior mirror assembly when such super-high power LEDS are used.Diffuser films and/or light control/brightness enhancement films, suchas the Vikuiti™ films described above, can be used in conjunction with abank of at least two, and preferably at least four high-power (each oflumens of at least about 15 lumens) LEDs.

Optionally, other configurations and methodologies may be incorporatedto provide enhanced viewing of the display at the mirror reflectiveelement, and reducing or substantially limiting washout on brightambient light conditions, such as encountered on a sunny day. It isknown to locate a video screen in a mirror assembly and behind themirror reflective element so that the display is transmitted through thereflective element for viewing by an occupant of the vehicle. Forexample, and as shown in FIG. 11, a video screen 136 may be located atthe rear surface 118 a of a glass substrate 118 of a reflective element112 (such as at and behind the fourth surface of an electro-optic orelectrochromic reflective element or cell, such as described above),such as by utilizing aspects described in U.S. Pat. No. 6,690,268, whichis hereby incorporated herein by reference in its entirety. The videoscreen 136 may be located at a window or aperture 120 a formed in amirror reflector coating (which can be second surface or third surfaceor fourth surface depending on the particular mirror construction) orlayer 120, such as is known in the art, such as formed by locallyremoving the mirror reflector layer to open up a transmissive window.The display images emitted by the video screen 136 thus are transmittedthrough the glass substrate or substrates 118 of the reflective elementfor viewing by an occupant of the vehicle at the local window in themirror reflector. In such an application, the display images may achieveup to approximately 100 percent transmission through the glass substrate(depending on any light absorbance in its path) for enhanced viewing ofthe display images. However, the mirror reflector (which may provideabout 80 percent or more reflectivity at the reflective element) isremoved at the display region, so that the display region is notreflective, except for reflectance off of the front surface of the frontglass substrate of the reflective element, and so the rearward field ofview of the reflective element is reduced and the presence of the videoscreen behind the local transmissive window created (such as by maskingor laser ablation) in the mirror reflector layer(s) is plainly visibleto the driver even when the video screen is not actuated to emit itsvideo image. Although shown in FIG. 11 (and in FIGS. 12-20, discussedbelow) as having a single glass substrate, the reflective element maycomprise a single glass substrate or front and rear glass substrates,such as front and rear substrates with an electrochromic medium disposedtherebetween as described above, without affecting the scope of thepresent invention.

In addition, placing a video screen in a mirror assembly (and behind themirror reflective element so that the display is transmitted through thereflective element for viewing by an occupant of the vehicle) is known,and it is also known to covertly locate the video screens behind thereflective element to provide a transflective DOD (Display-on-Demand)display through the transflective reflective element, such that thepresence of the video screen is only noticeable or discernible when thevideo screen is activated, such as by utilizing aspects described inU.S. Pat. Nos. 6,690,268; 5,668,663 and/or 5,724,187, and/or in U.S.patent application Ser. No. 10/528,269, filed Mar. 17, 2005, now U.S.Pat. No. 7,274,501; Ser. No. 10/533,762, filed May 4, 2005, now U.S.Pat. No. 7,184,190; Ser. No. 10/538,724, filed Jun. 13, 2005 andpublished Mar. 9, 2006 as U.S. Publication No. US-2006-0050018; Ser. No.11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 as U.S.Publication No. US-2006-0061008; Ser. No. 11/284,543, filed Nov. 22,2005, now U.S. Pat. No. 7,370,983, which are all hereby incorporatedherein by reference in their entireties. As shown in FIGS. 12 and 13, adisplay screen 136′ may be located behind the glass substrate orsubstrates 118′ of a reflective element 112′ and behind a transflectivemirror reflector 120′, so that the display images are transmittedthrough the transflective mirror reflector and through the glasssubstrate or substrates 118′ of the reflective element. Such anapplication may provide about 10 to 30 percent transmission or morethrough the transflective reflector and the reflective element, whilethe mirror element may be about 50 to 70 percent or so reflective oflight incident thereon. However, the intensity of the video display isreduced (relative to the intensity that would be achieved by thereflective element 112 of FIG. 11, discussed above) by the transflectivemirror reflector, since the display illumination is transmitted throughthe transflective mirror reflector. The video image thus may be viewedor seen against the glass surface reflected image (which may reflectabout 4 percent or thereabouts of light incident thereon) and againstthe mirror reflector reflected image. Although shown as having atransflective reflector at the rear of the reflective element, thetransflective reflector may be located at the third surface (the frontsurface of the rear substrate of the reflective element) or at thefourth surface (the rear surface of the rear substrate of the reflectiveelement) of the reflective element.

Such applications as shown in FIGS. 11-13 provide adequate performancefor the particular applications at which they are implemented. However,such applications may encounter display washout during high ambientlighting conditions, such as typically encountered on a sunny day. Asunny day can have a brightness or luminance of about 4,000 nits(candelas per meters squared) or more, which is substantially higherthan a dull or cloudy day, which may have a brightness or luminance ofonly about 6 to 120 nits (such that a sunny day may have about 300 timesthe brightness or luminance than a dull day). FIGS. 21 and 22 showexamples of different luminance levels and brightness for typicallighting conditions.

A driver of the vehicle typically aligns the rearward field of view ofthe interior rearview mirror to fill or at least substantially fill therear window (such that the mirror's rearward field of view issubstantially framed around the rear window of the vehicle through whichsunlight streams in). When so aligned, the mirror reflector may reflectabout 80 percent or more of the light streaming through the rear windowto the driver's eyes. Even if the rear window comprises substantiallytinted glass, the driver may still see a mirror reflected image ofseveral hundred nits brightness, such as of about 1,000 nits or more ona bright sunny day. Thus, the display projected or emitted by the videoscreen will be washed out due to the high intensity of the light fromthe rear window that is reflecting off of the mirror reflective element.

A typical LCD video screen, such as a TFT backlit LCD video screen mayprovide a brightness of about 300 to 500 nits, while a typical plasmavideo screen may provide a brightness of about 700 to 1000 nits or more.Although various contrast enhancements can be used to reduce displaywashout, as discussed above, such enhancements may not be fullyeffective in terms of eliminating washout in conventional transflectivemirror reflective element applications, since the video screen islocated behind the mirror reflector in DOD transflective interior mirrorapplications, and the intensity of the video display is reduced onpassage through the mirror reflector. Because the mirror reflector onlypartially transmits the video image, the image can be washed out on asunny day by the brighter reflected image of the mirror itself. As shownin FIG. 13, in order to be viewable, the display image of the videoscreen 136′ must be seen against the glass surface (such as the firstsurface of the mirror reflective element) reflected image (typicallyabout 4 percent reflectant of light incident thereon) and against themirror reflector reflected image (typically about 70 to 80 percentreflectant or more of light incident thereon). Thus, the display imagefrom the video screen must be seen in contrast against the brighterreflection off the mirror reflector itself.

Optionally, and as shown in FIG. 14, a contrast enhancement means, suchas a local polarizer trap 140 may be disposed between the video displayscreen 136″ and the mirror reflector 120″ (such as at the rear surfaceof the glass substrate 118″) of the reflective element assembly 112″.The video screen 136″ emits polarized light that passes through thepolarizer trap 140, such as described above, while the polarizer trap140 may trap unpolarized sunlight to limit or reduce the amount ofdisplay washout. However, because the video screen and polarizer trapare located rearward of the mirror reflector, the polarizer light trapmay not fully effectively trap the light reflected directly off of themirror reflector itself.

Another option to implement to enhance display viewability and reducedisplay washout is to increase the intensity of the video displayscreen. For example, Optrex America Inc. offers a 10.4 inch diagonalhigh brightness TFT transmissive LCD module with high contrast andresolution. With a brightness of about 550 nits, it provides enhancedbrightness over other known display screens. The screen resolution isabout 800×RGB×600, with a contrast ratio of about 180:1. Also, lightemitting diodes (LEDs), cold cathode lighting and organic light emittingdiodes (OLEDs) that are selected to be bright and efficient may be used.Heat management and light leakage through a pixel “off” state should beminimized. Optionally, a plasma display (such as an enhanced plasmadisplay utilizing aspects of a bright plasma display, such as used inthe Samsung PS42D5S plasma screen, which provides a brightness of about1500 nits) or an LED display can be used as a video screen.

Another option to enhance viewing of a video display is to locate thedisplay outside of the direct field of view of the interior rearviewmirror through the rear window. As can be seen in FIG. 15, thereflective element (typically a prismatic mirror element or anelectrochromic mirror element) of a typical interior rearview mirrorassembly may be aligned so as to have a rearward field of view A throughthe rear window of the vehicle. As shown in FIGS. 16 and 17, length ofthe reflective element of the mirror assembly 210 may be increased insize so that the passenger-side length is increased by about 2½ to 3inches (relative to where the support arm attaches) so as to accommodatethe video screen (such as described in U.S. Pat. No. 6,690,268, which ishereby incorporated herein by reference in its entirety). The videoscreen 236 may be located at the outer, expanded passenger side region210 a of the asymmetric mirror assembly, and thus may have a field ofview B that is outside the field of view A through the rear window (andthus not directly subject to sunlight streaming in through the rearwindow on a sunny day). By placing the video screen outside the directfield of view through the rear window, the mirror assembly maysignificantly reduce display washout on sunny days.

Optionally, the reflective element may have a locally dimmed displayarea so as to provide dimming or darkening of the display area to reducethe reflectivity at the display area and, thus to reduce display washouton sunny days, such as by utilizing aspects of U.S. Pat. No. 6,690,268,which is hereby incorporated herein by reference in its entirety. Forexample, and as shown in FIG. 18, a reflective element 312 may have amain or principal electrochromic reflective area or portion or region312 a and a display reflective area or portion or region 312 b. Theseparate areas or regions 312 a, 312 b may be defined and separated by athin demarcation or deletion line or lines (not shown) formed in eitheror both of the second and third surface conducting layers at the secondand third surfaces, respectively, of the reflective element and at theelectrochromic medium (also not shown) disposed between the front andrear substrates 318, so as to electrically isolate different regions ofthe electrochromic reflective element. Thus, the video display 336 maybe located behind the transflective reflector 320 at the display area312 b. When the display area 312 b is locally darkened or dimmed, thedisplay area has a reduced reflectance of light incident thereon. Forexample, the display area may have only about 20 percent (or more orless depending on the degree of dimming of the display area) reflectionof light incident thereon when locally dimmed or darkened, as comparedto about 70 percent reflection of light incident thereon when bleachedor not darkened. Thus, the display image projected through the mirrorreflector and through the reflective element at the darkened displayarea 312 b may achieve reduced washout on sunny days, while theprincipal viewing area or reflecting area 312 a of the reflectiveelement provides substantial reflectance of light incident thereon.

Accordingly, when the reflective element locally dims in reflectance dueto electrochromic activity local to display area 312 b, the intensity ofany sunlight incident on transflective reflector 320 at this localdisplay area is twice-attenuated by the electrochromic medium whereasthe light emitted by the display is only once attenuated by theelectrochromic action local to where it is positioned at the displayregion. Hence, contrast is enhanced (but since the display zone iselectrically isolated from the main mirror area, the rest of the mirrorneed not dim when the display area locally dims). Theelectrically-isolating deletion (such as is described in U.S. Pat. Nos.6,002,511; 5,724,187; 5,668,663 and 5,910,854, which are herebyincorporated herein by reference in their entireties) between thedisplay zone 312 b and the main reflector zone 312 a may be created suchas by the likes of laser ablation of the conductive coating(s) of theelectrochromic reflective element at the display region (such as in thethird surface metallic reflector layer and/or in the second surfacetransparent conductor, such as an ITO layer, of a laminate-typeelectro-optical mirror cell) so as to electrically isolate the displayregion from the principal viewing/reflecting region of the mirrorelement, so that when the display region dims to a lower reflectivity(and hence the display intensity of the video display screen is reducedbut sunlight is locally doubly-reduced), the region of the mirrorreflector outside of the display region (i.e., the main or principalviewing or reflecting region of the mirror element) does not necessarilydim in reflectivity (and so can be used to view rearward when reversingand the like). But at night, both the display region and the principalviewing region of the mirror reflective element may dim in tandem whenglare from a following vehicle is detected by the glare sensor of theautomatic dimming interior mirror assembly (optionally, when the glareis being detected but there may be a desire also to actuate the videodisplay screen to display a video image or information display or thelike, the region of the EC medium local to and in front of the videoscreen may dim less than the dimming of the principal viewing region ofthe mirror reflector so that the visibility to the driver of theinformation being displayed by the video display is preserved).

The video display screen is thus disposed behind the electrochromicmirror reflective element at the display region, with the reflectiveelement divided by a partition into different zones, such as describedin U.S. Pat. No. 6,690,268, which is hereby incorporated herein byreference in its entirety. The zones are individually controllable inreflectivity by a control (that preferably includes a photo sensorresponsive to ambient light intensity levels local to the mirrorassembly). The mirror assembly may comprise an epoxy seal material, suchas used in the electrochromic arts and such as disclosed in U.S. Pat.Nos. 6,002,511; 5,680,245; 5,066,112; 5,724,187; 5,668,663 and5,910,854, which are hereby incorporated herein by reference in theirentireties.

Desirably, the display zone is only colored or darkened or dimmed whenneeded, in order to limit the potential spectral effects (and henceeffect on the likes of color rendition or the like) on the display imagethat may occur when EC medium at the display regions is locallydarkened. Thus, the display zone or region may be controlled in responseto an ambient light sensor. Optionally, the photosensor or ambient lightsensor may be located behind the display zone region so as to receivelight through the separately dimmed region at the display screen, or thesensor may be located elsewhere, such as at the principal viewing areaof the reflective element (such as behind the transflective reflectoritself). The display zone or region of the reflective element may belocally dimmed or darkened when the ambient level of light detected atthe mirror assembly reaches or exceeds a threshold level. Optionally,the display zone or region may be controlled in response to the existinglight sensor used to control the principal viewing area of thereflective element (such as the ambient sensor common on automaticdimming mirror assemblies or another ambient light sensor of thevehicle).

Optionally, the zones may be controlled in response to engagement of thereverse gear of the vehicle. For example, when the vehicle is shiftedinto reverse, the display zone may be automatically dimmed or partiallydimmed or colored to provide the desired contrast for the display (suchas a display that provides images of the rearward field of view for areverse aid or rear vision system of the vehicle) when the driver isbacking up or reversing the vehicle (but the main or principal reflectorarea remains undimmed and high reflecting). Thus, the rear vision systemmay automatically activate the display screen and may automatically dimthe display region or zone of the mirror reflective element when thevehicle is shifted into reverse for a reversing maneuver while leavingthe remainder of the mirror element undimmed.

The two zones or regions of the mirror reflective element thus areindividually controllable in reflectivity by a control (not shown),which preferably includes a photo sensor responsive to ambient lightintensity levels local to the mirror assembly. During daytime driving,the control may power the display zone alone to reduce lighttransmission (for example, by dimming to about a 20 percent to 30percent transmission level in the display zone for the electrochromicmedium of the display zone) so that contrast enhancement for the imagebeing displayed by the video display screen is provided. At night, thecontrol may power both of the zones (either in tandem or selectively orlocally) to provide glare protection from trailing headlights.

Optionally, an anti-reflection coating may be disposed at the frontsurface of the reflective element and at the display area to reduce thefirst surface reflection at the display area to reduce display washout,such as by utilizing aspects described in U.S. Pat. No. 5,076,674, whichis hereby incorporated herein by reference in its entirety. For example,and as shown in FIG. 19, a reflective element assembly 312′ may includean anti-reflection coating or layer or element 342 at the front surfaceof the reflective element and generally in front of the video display336′ disposed behind the glass substrate or substrates 318′ and behindthe transflective mirror reflector 320′. The display images emitted orprojected by the video display thus are transmitted through the mirrorreflector 320′, through the substrate/substrates and through theanti-reflection coating 342. The anti-reflection coating 342 functionsto reduce the first surface reflection at the mirror first surface, suchas from about 4 percent reflectance of light incident thereon to about0.5 percent reflectance of light incident thereon. The anti-reflectioncoating 342 thus may provide reduced display washout on a sunny day.

Optionally, the video screen may be disposed at the rear of thereflective element and at an angle relative to the substrate orsubstrates of the reflective element, so that the display image isemitted/projected through the reflective element at an angle relative tothe reflective element. For example, and as shown in FIG. 20, a videodisplay screen 436 may be disposed at the rear of a reflective element412 and may be angled relative to the rear surface 412 b and mirrorreflector 420 of the reflective element. The video display of the videoscreen 436 thus is transmitted through the reflective element at anangle that is different than the angle of the light reflecting off themirror reflector 420 and the light reflecting off the front or firstsurface 412 a of the reflective element 412.

Optionally, the video display screen may comprise a scanning beamdisplay system that includes a plurality of laser light sources ordiodes, a controller and a micro-electromechanical scanner (MEMS), suchas the types described in U.S. patent application Ser. No. 11/226,628,filed Sep. 14, 2005 and published Mar. 23, 2006 as U.S. Publication No.US-2006-0061008, which is hereby incorporated herein by reference in itsentirety. Such a direct laser-write video can deliver display intensityof about 1500 nits or more. Because of the high intensity illuminationprovided by such laser diodes, the intensity at the display region ofthe reflective element will be sufficient to dominate the reflection ofthe rearward scene off of the front surface of the front substrate ofthe reflective element, and thus will not appear washed out, even duringhigh ambient lighting conditions, such as typically encountered on asunny day. Optionally, the intensity of the laser diodes may beadjusted, such as via manual adjustment and/or via automatic adjustment,such as in response to the ambient light levels in the cabin of thevehicle or in the vicinity of the display.

Optionally, and with reference to FIG. 23, a mirror reflector element512 includes a transmissive element 518, which may comprise a rearsubstrate for a laminate-type electrochromic (EC) mirror element(whereupon, as indicated below, reflector layer or layers 520 may be onthe third or fourth surface of the laminate EC cell construction), orwhich may comprise a substrate for a conventional (non-EC) mirrorelement (such a single mirrored glass substrate) having a reflectorlayer or layers 520 at the rear or back surface of the transmissiveelement 518. Reflector 520 is divided or separated (or optionally,electrically isolated) into two portions or regions, a highly reflectingmain or principal reflector portion (that is highly reflecting but neednot be light transmitting) constituting a principal viewing/reflectingregion portion 520 a at the principal viewing region (zone B) of themirror reflective element and a display region portion 520 b where thereis established a transflective reflector (significantly lighttransmitting and light reflective) and where a video display or otherinformation display device is disposed. For purposes of electricalisolation (and only needed if it is desired to enable that the EC mediumat display zone A be dimmable independent of any dimming of the ECmedium at main reflector zone B (and so achieve the video image contrastenhancement/reduced wash-out described above whereby the EC medium canlocally dim in front of where the video screen 536 is disposed when, forexample, the driver is reversing the vehicle on a sunny day, while theremainder of the EC medium stays undimmed so that driver retains highreflectivity at zone B so he/she can see clearly while backing up thevehicle or the like)), a demarcation or deletion line 519 is established(such as by laser ablating a deletion line through the transflectivelayer established at the rear of the substrate) close to the interfacebetween the portions 520 a, 520 b to electrically isolate the portionsfrom one another. The rear substrate of the EC mirror element thus mayinclude a display region transflective reflector layer or layers 521disposed at a display region (zone A) of the mirror reflector element512, and preferably contacting or overlapped by (or overlapping) thereflector 520, such as the display region reflector portion 520 b or themain reflector portion 520 a of reflector 520.

Preferably, for an EC laminate-type mirror element that uses a thirdsurface reflector, the partially transmissive and still significantlyreflective transflective reflector layer or layers 521 is firstdeposited onto the interior mirror shaped glass substrate (typically,though a polymeric substrate such as a polycarbonate or an acrylic or aCR39 or a COC can be also be used) at the display region or zone A, suchas by sputter deposition in a vacuum chamber and with the “zone B”portion of the substrate masked. Then, in a second deposition step andwith the mask removed, a different (less or non-transmissive but highlyreflective) main or principal reflector layer or stack of layers [thatis highly reflecting (>80% R preferred) but that need not be lighttransmitting at all since the video display is not disposed therebehind]can be deposited to form the reflector 520 in a manner that overlaps theedge of the already established display zone A transflective reflectorlayer or layers 521. Thus, there can be perfect register between the twozones. The (optional) thin demarcation line 519 can be then establishedclose to where the respective layer(s) of zone A and zone B overlap. Thedriver will likely notice a slight difference in reflectivity betweenthe less reflecting transflective reflector at zone A and the morehighly reflecting reflector at zone B, but this need not be problematic,and the video screen 536 is still largely covertly hidden by thetransflective reflector at zone A, and the greater light transmissivityof zone A (in the range of about 25% T to about 45% T at zone Aachievable while still maintaining reflectivity off the EC mirrorelement at zone A of at least about 50% R) helps ensure that displaywashout on a sunny day is reduced. The video display screen 536 isdisposed to the rear of the display region transflective layer 521 andis operable to emit a video image and through the transmissive mirrorelement 518 and through the display region transflective layer 521 forviewing by a driver of the vehicle.

As shown in FIG. 23, layer or layers 520, 521 comprise a thin metalliclayer sandwiched between transparent conductive layers (but otherembodiments are possible such as use of a single thin silver or sliveralloy layer or uses of a bi-layer). In a preferred illustratedembodiment, reflector 520 comprises a transparent conductive layer 523a, such as ITO, of about 12 nm (120 Angstroms) thick, a metallic layer523 b, such as silver, of about 80 nm thick, and a transparentconductive layer 523 c, such as ITO, of about 12 nm thick. Such areflector or stack of coatings or layers may provide at least about 80percent reflectivity of light incident thereon (even when viewed as athird-surface in an EC mirror cell element), so that the mirrorreflective element is at least about 70 percent reflective (when the ECmirror element is bleached or not dimmed) of light incident on zone B.Transmission through reflector 502 is minimum (typically less than about2% or so).

Similarly, for example, transflective reflector 521 comprises atransparent conductive layer 525 a, such as ITO, of about 15 nm (150Angstroms) thick, a metallic layer 525 b, such as silver, of about 22 nmthick, and a transparent conductive layer 525 c, such as ITO, of about70 nm thick (though other variants, such as described above, may beused). Such a transflective reflector may provide about 50 to 60 percentreflectivity of light incident on zone A through the EC mirror element(when the transmissive element is bleached or not dimmed), whileallowing about 10 to 40 percent transmission of light through the mirrorreflective element (when the transmissive element is bleached or notdimmed). Thus, the mirror reflective element may have enhancedtransmissivity at the display region (zone A), while providing a desireddegree of reflectivity of light incident thereon. An exemplarytransflective mirror reflective element comprising glass/15 nm ITO/22 nmsilver metal/70 nm ITO, such as described above, achieves thecharacteristics of light transmission/reflectance at the mirrorreflective element as shown in FIGS. 24 and 25. As shown in FIG. 24,light passing through the mirror reflective element at zone A (and thusthrough the transflective layer 521 and through the glass substrate 518)has a luminosity percent of about 57 percent reflecting and about 37percent transmitting, and with the mirror reflectance beingsubstantially spectrally neutral so as to appear “silvery” to theviewer.

Other means may be implemented to provide a display screen at the mirrorassembly that achieves reduced display washout on a sunny day. Forexample, a video slide-out mirror with a video display screen thatslides out or otherwise extends to a viewable position when it isactivated, such as a video mirror of the types described in U.S. Pat.No. 6,690,268, and/or U.S. patent application Ser. No. 11/284,543, filedNov. 22, 2005, now U.S. Pat. No. 7,370,983; and/or Ser. No. 10/538,724,filed Jun. 13, 2005 and published Mar. 9, 2006 as U.S. Publication No.US-2006-0050018; PCT Application No. PCT/US03/40611, filed Dec. 19, 2003and published Jul. 15, 2004 as International Publication No. WO2004/058540, and/or U.S. provisional applications, Ser. No. 60/630,061,filed Nov. 22, 2004; and Ser. No. 60/667,048, filed Mar. 31, 2005, whichare hereby incorporated herein by reference in their entireties.

Also, in situations at night where a trailing vehicle to the rear of avehicle equipped with an automatic dimming electrochromic (EC) interiorrearview mirror has its high beam head lamps on or in similar highglaring conditions when driving at night, it is advantageous to have theinterior electro-optic mirror dim close to 4 percent reflectivity in itsanti-glare fully dimmed mode. With the likes of sodalime glass formingthe first surface of the front or first substrate that incoming light isincident on, Fresnel's Laws of Reflection ensure that reflectivity willbe at least 4% R (measured as per SAE J964a, which is herebyincorporated herein by reference in its entirety) and so compliance withFMVSS 111 is assured. To achieve a reflectivity close to 4% R from alaminate-type electro-optic (such as an electrochromic) interior mirrorcell that comprises a front and a rear substrate with an electro-opticmedium (such as an electrochromic medium) sandwiched therebetween (andso having a first, a second, a third and a fourth surface, such as areknown in the art), it is desirable to have the electrochromic medium dimvery darkly so that reflections off the third and fourth surfaces of thelaminate-type electrochromic cell are minimized, and also it isdesirable to have any reflections off the second surface also benegligible. For conventional laminate-type interior electrochromicmirrors used on vehicles today, transmission through the fully dimmed ECmedium is typically about 15% T to about 17% T or so, and reflectivityoff the EC mirror element is typically in the about 6% R to about 10% Rrange. Suppliers of such mirrors typically have to meet a <10% R(sometimes less than 8% R) fully-dimmed reflectivity statespecification. Consequently, many of the interior EC mirrors used invehicles today dim (at about 23 degrees Celsius or so) no lower than 6%R and only a relatively few dim in the 5% to 6% R range. To consistentlymanufacture and ship interior EC mirrors that consistently (across theannual volume manufactured within, for example, at least about 1 sigmaof, more preferably within at least about 2 sigma of and most preferablywithin at least about 3 sigma of) dim below 5% R and preferablyconsistently dim to below 4.75% R and more preferably consistently dimto less that about 4.5% R and most preferably consistently dim to closeto or lower than 4.25% R (but still be higher than 4% R), we find itadvantageous to use a cell interpane gap of at least about 150 microns(more preferably at least about 175 microns and most preferably greaterthan about 200 microns) to contain the EC medium sandwiched between thefront and rear substrate of the laminate-type EC cell construction. Wealso find it advantageous to use a relatively high concentration ofelectro-optically active species in the EC medium. For example, aconcentration of cathodic organic species (such as viologen orviologens) of at least about 0.055 M is preferred (more preferably atleast about 0.065 M and most preferably at least about 0.075 M) as wellas a similarly high concentration of anodically coloring species, suchas phenazines or ferrocenes (more preferably at least about 0.06 M andmost preferably at least about 0.07 M). We find it advantageous to use asilver or silver-alloy third surface reflector (such as a glass/metaloxide/Ag/metal oxide third surface reflector such as glass/ITO/Ag (or Agalloy)/ITO, or such as a glass/Cr/Ag (or Ag alloy)/Al:ZnO third surfaceelectrode or such as a glass/silver or glass/silver-alloy third surfacereflector). We also find it advantageous to use a metal borderelectrical conductor band (such as disclosed in U.S. patent applicationSer. No. 11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 asU.S. Publication No. US-2006-0061008, and/or U.S. provisionalapplications, Ser. No. 60/750,199, filed Dec. 14, 2005; Ser. No.60/681,250, filed May 16, 2005; Ser. No. 60/690,400, filed Jun. 14,2005; Ser. No. 60/695,149, filed Jun. 29, 2005; Ser. No. 60/730,334,filed Oct. 26, 2005; Ser. No. 60/750,199, filed Dec. 14, 2005; Ser. No.60/774,449, filed Feb. 17, 2006; and Ser. No. 60/783,496, filed Mar. 18,2006; and/or PCT Application No. PCT/US2006/018567, filed May 15, 2006and published Nov. 23, 2006 as International Publication No. WO2006/124682, which are hereby incorporated herein by reference in theirentireties.) around and preferably fully circumscribing the borderperimeter of the second surface of the front substrate so that there isa highly conductive all-around electrically conductive raceway aroundthe ITO (or similar transparent electronic conductor coating orcoatings) on the second surface of the front substrate. Flush ornear-flush constructions are preferred (such as disclosed in U.S. patentapplication Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S. Pat. No.7,255,451; Ser. No. 10/528,269, filed Mar. 17, 2005, now U.S. Pat. No.7,274,501; Ser. No. 10/533,762, filed May 4, 2005, now U.S. Pat. No.7,184,190; and/or Ser. No. 11/226,628, filed Sep. 14, 2005 and publishedMar. 23, 2006 as U.S. Publication No. US-2006-0061008, which are herebyincorporated herein by reference in their entireties), and use of amaximum powering voltage of at least about 1.3 volts is preferred, morepreferred at least about 1.35 V and most preferred at least about 1.4 V.Also, the composition and optical thickness and optical constants(including refractive index) of the transparent conductor (such as ITO)used on the second surface of the front substrate is selected andadapted to minimize any visible light reflectance off this secondsurface interface (and if beneficial, additional anti-reflection layersand means, as known in the optical arts, can be used to reduce oreliminate such second surface reflections). Transmission through the ECmedium for such very dark dimming interior mirror EC cells is preferablyless than about 13% T, more preferably less than about 8% T and mostpreferably is less than about 3% T when fully dimmed under the maximumapplied voltage delivered by the EC mirror element powering circuitry ofthe automatic dimming interior mirror assembly. Note that aspects ofsuch improvements in delivery of darker dimming electrically variablereflectivity interior automotive mirrors may also be applied toelectrically variable reflectance automotive exterior mirrors.

Referring now to FIGS. 26-30, an interior rearview mirror assembly 610for a vehicle (such as part of a video mirror system of the vehicle)includes an electro-optic element assembly or cell 612 and a displaydevice 614 at a rear surface of the electro-optic element 612 fordisplaying information at a display area 615 of the reflective element.Display device 614 comprises a liquid crystal display module or LCM andis located behind the reflective element so as to be viewable by adriver of the vehicle when activated (such as shown in FIG. 26B), yetsubstantially non-viewable by or non-visible to the driver whendeactivated (such as shown in FIG. 26A). Mirror assembly 610 may utilizeaspects of the mirror assemblies described in U.S. patent applicationSer. No. 11/284,543, filed Nov. 22, 2005, now U.S. Pat. No. 7,370,983;and/or Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S. Pat. No.7,255,451; and/or PCT Application No. PCT/US2006/018567, filed May 15,2006 and published Nov. 23, 2006 as International Publication No. WO2006/124682, which are all hereby incorporated herein by reference intheir entireties.

It is desirable that the display device provides enhanced or substantialbacklighting of the display screen to enhance the viewability of thedisplay screen during high ambient lighting conditions. However,enhanced illumination typically results in increased operatingtemperatures of the display device due to the heat dissipation by thelight sources of the rear backlighting, and, thus, is often challengingfor applications within an enclosed structure such as a mirror casing.In the illustrated embodiment, the display device or video displaymodule 614 includes sixty-four white light emitting diodes (LEDs) thatare operable to backlight an LCD display screen 624, as discussed below.In order to reduce the operating temperature at the display device ormodule, mirror assembly 610 includes one or more thermally conductiveelements or heat dissipating elements or heat slugs 616, 617 toconduct/dissipate heat generated by the LCM display device 614, as alsodiscussed below.

As shown in FIG. 27, mirror assembly 610 includes a bezel portion 618and a rear casing or housing 620 that support the reflective element 612at the vehicle. Mirror assembly 610 includes a light mask or maskingelement 622 disposed at a rear surface of the reflective element 612(which comprises a transflective or transreflective display on demandreflective element, such as the types described above). Light mask 622comprises a dark or opaque material and substantially covers the rear ofthe reflective element and defines a window or aperture 622 a at therear of reflective element at which the video screen 624 of the displaydevice 614 is located when the mirror is assembled. Optionally, themirror assembly may include various masking configurations or the liketo reduce viewability of the video screen at the mirror when the videoscreen is deactivated or not backlit or not illuminated. For example,the mirror assembly may include a masking element that includes orsubstantially matches the appearance of the deactivated or notilluminated video screen or the polarizer at the forward surface of thevideo screen, or the mirror assembly may include a video display framingelement or pocket, such as a piece of metal shim stock (such asdescribed in PCT Application No. PCT/US2006/018567, filed May 15, 2006and published Nov. 23, 2006 as International Publication No. WO2006/124682, which is hereby incorporated herein by reference in itsentirety) that has a window formed or laser cut therefrom that matchesor substantially matches the size and shape of the active area of thedisplay screen. Desirably, the color, reflectance and gloss of the shimstock substrate is selected to substantially match the OFF condition ofthe video display screen. The presence and location of the video displayis thus substantially camouflaged or hidden or non-discernible so thatit may be difficult to identify or discern the location of the videodisplay when viewing the reflective element. The display assembly(including the masking element or shim stock plate and display elementattached thereto) may be attached or adhered to or disposed at the rearof the reflective element. Optionally, the mask element or material maynot include a window for the display screen, but may comprise apolarizing material so that the video screen is located at thepolarizing material and operable to emit light therethrough whenactivated, yet is substantially non-viewable behind the polarizingmaterial when the display module and video screen are deactivated or notilluminated. The video display module may be attached to or adhered tothe masking element and/or the rear surface of the reflective element,such as via a double-sided adhesive or tape 643.

An attachment plate 626 is attached at the rear of the reflectiveelement 612, such as at a rear surface of the light mask 622, such asvia a double sided adhesive tape 628 or the like. Similarly, the liquidcrystal display module 614 is attached at the rear of the reflectiveelement, such as via a double sided adhesive tape, such as via atransparent tape or adhesive material. A printed circuit board 630 isattached to the attachment plate 626 and includes circuitry disposedthereon with a wire harness 631 extending therefrom for connection to avehicle wire harness or power source or control.

The attachment plate 626 includes a mounting ball member 626 a (whichmay be insert molded at the attachment plate or otherwise attached ormounted thereto or established thereat, such as by using aspects of theattachment elements described in U.S. patent application Ser. No.11/226,628, filed Sep. 14, 2005 and published Mar. 23, 2006 as U.S.Publication No. US-2006-0061008; and/or Ser. No. 10/933,842, filed Sep.3, 2004, now U.S. Pat. No. 7,249,860, and/or PCT Application No.PCT/US04/015424, filed May 18, 2004 and published Dec. 2, 2004 asInternational Publication No. WO 2004/103772, which are herebyincorporated herein by reference in their entireties) for pivotallymounting the mirror to a mounting structure or mounting arm 627 a andmounting button or channel mount 627 b for attaching the mirror to aninterior surface of a vehicle, such as to an interior surface of thevehicle windshield or to an overhead console or headliner or the like.The mounting arm 627 a extends through an aperture 621 establishedthrough a central region of the mirror casing 620 when the mountingconfiguration and mirror assembly is assembled. The wiring harness 631may be along the mounting arm 627 a and may be contained or routedwithin a wire clip 633 (which may snap or otherwise attach to themounting arm to route and contain the wiring harness along the mountingarm, such as by utilizing aspects of the mounting arrangements describedin U.S. provisional application, Ser. No. 60/729,430, filed Oct. 21,2005, and/or U.S. patent application Ser. No. 11/584,697, filed Oct. 20,2006, now U.S. Pat. No. 7,510,287, which are hereby incorporated hereinby reference in their entireties). Optionally, the attachment plate mayinclude a plurality of strengthening ribs 626 b to enhance thestructural rigidity of the attachment plate to enhance the support ofthe mirror assembly in the vehicle. Optionally, the attachment plate maycomprise an ABS material or may comprise a glass filled NYLON® materialor the like to provide enhanced structural rigidity and strength overknown plates made of an ABS material or the like.

Because either or both of the video display device or module 614 and/orthe circuitry of the circuit board 630 may generate heat during use, itis desirable to reduce or minimize the heat build-up within the mirrorassembly. For example, the illumination source 640 of the display modulemay comprise a plurality of individual low powered LEDs (such as whiteNichia NESW064 LEDs or the like), each operating at up to about 50 mA(and typically at about 20 mA), and typically with a forward voltage ofabout 2 volts to about 5 volts (typically about 3.5-4 V). Thus, each LEDmay generate up to about 0.1 watts, and the array of sixty-four LEDs maydissipate up to about 6 watts (typically 3-6 watts and typically about 4watts). Desirably, the sixty-four LEDs of the display module are poweredas two banks of LEDs, with each bank having thirty-two LEDs, and withthirty-two sets or pairs of two LEDs being powered in series, with 8.5volts across each series and a current regulator in series with eachpair of LEDs. When so powered, the sixty-four white LEDs generate alight intensity of about 30,000 candelas/m² (thus, one or two or morebanks of at least about 30 white LEDs (or more or less banks and/or LEDsdepending on the particular application) is used, generating abacklighting intensity of at least about 10,000 candelas/m², morepreferably at least about 20,000 candelas/m², and more preferably atleast about 30,000 candelas/m²), which provides a super high intensitybacklight for a video screen and is achieved in a substantially squareor rectangular array or package that is only about 2.5-3.5 inchesdiagonal or thereabouts. Although shown and described as sixty-four LEDscomprising two banks of thirty-two LEDs, more or less LEDs and/or moreor less banks may be implemented, and each bank may include more or lessthan thirty-two LEDs, depending on the particular application of theLEDs and backlighting device and LCD video display screen and displaymodule.

In the illustrated embodiment, the super high intensity backlight orillumination source 640 is positioned behind the display screen 624,which comprises a thin film transistor (TFT) LCD video screen with apolarizer or polarizing element, and emits the light through the videoscreen and through the transflective mirror reflective element forviewing by the driver of the vehicle. Such an LCD screen with polarizermay transmit about 5-10 percent of light incident thereon and typicallyabout 6-7 percent of light incident thereon. When positioned in front ofthe LEDs (with an intensity of about 30,000 candelas/m²), the lighttransmitted by the LCD may have an intensity of about 3,000 candelas/m²,which provides a super bright LCD video screen.

The LCD screen is positioned behind the transreflective or transflectiveelectro-optic (such as electrochromic) mirror reflective element 612,which may have at least about 10 percent transmissivity of lightincident thereon, preferably at least about 15 percent transmissivity oflight incident thereon, and more preferably about 20 percenttransmissivity of light incident thereon, and less than about 30 percenttransmissivity. Such a transflective reflective element may provide atleast about 60 percent reflectivity of light incident thereon and morepreferably at least about 65 percent reflectivity of light incidentthereon. Thus, the intensity of the light from the display screen thatis transmitted through the reflective element is about 400-600candelas/m², which is highly visible to the driver of the vehicle.

Thus, the display module of the present invention provides a super highintensity backlight for a video screen so as to enhance the viewabilityof the video screen. However, such a super high intensity backlightgenerates heat at the display module and it is desirable to dissipatethe heat and draw the heat away from the display module to avoid burningout of the LEDs or other electrical components and circuitry. In theillustrated embodiment, the LEDs are powered via a 12 volt feed from thevehicle, which is stepped down or reduced to (such as via a voltageregulator or converter or resistor or the like) the 8.5 volts applied toeach pair of LEDs, such as via a converter or resistor or voltageregulator. The pairs of LEDs are powered at 20 mA and at 8.5 volts.Thus, with 32 pairs of LEDs powered at 20 mA and with a voltagereduction of about 3.5 volts (12 volts-8.5 volts), the powering of theLEDs generates about 2 watts. It is thus also desirable to dissipate theheat generated by the circuitry in powering the LEDs as well as todissipate the heat generated by the LEDs themselves when so powered.

Typically, it is desired that the display provide about 1000 nits as aminimum intensity for daytime viewability, such as is typically desiredfor laptops, digital cameras, and/or the like. With respect to videomirrors for vehicles, the intensity is targeted to provide an intensityof at least 500 nits and preferably 1000 nits or more. However, theintensity provided by the display is often limited due to the systemcapabilities and thermal concerns of the mirror assembly.

Optionally, it is envisioned that the mirror assembly display mayincorporate a “super-boost” intensity for daytime viewability, such asan increase in output intensity for a short period of time, such as forless than one minute or thereabouts. For example, the display mayoperate in the “super-boost” mode for up to about one minute when the onboard photo-sensors determine that a maximum day time intensity isrequired (and when the display is activated, such as when the vehicle isshifted into a reverse gear). Such a super-boost mode may be achieved bypushing an increased or maximum current through the back light LEDs orby providing a parallel drive line that can drive the display at ahigher current during the super-boost mode, and then switch over toanother drive line with reduced current drive on the back light LEDs fornormal operation of the display (such as for when the ambient light isbelow a threshold level as detected by one or more sensors). Optionally,and desirably, the intensity of the back light LEDs may be furthercontrolled via a pulse width modulation (PWM) signal from a control ormicroprocessor of the mirror assembly or display device, so as toprovide additional dimming capability to the display.

Optionally, for example, the control may drive the current through theback light LEDs at about 20 mA or less (such as just under 20 mA orthereabouts) with a PWM signal to achieve a display intensity of up toabout 800 nits. The LEDs may be able to handle up to about 30 mAcontinuous current, and if such a current were pushed through the LEDs,the LEDs would give the back light a boost above 1000 nits. It isenvisioned that if such a boost were provided for about 30 to 60seconds, the display should be at the high intensity or boosted displayintensity for a sufficient time to accommodate most backing upsituations under maximum intensity requirements. By limiting the boostedor super high intensity time to about 30 or 60 seconds, the displayoperation will reduce or minimize the thermal impact to the system whileproviding a better potential for achieving the initial goal ofviewability in high ambient lighting conditions, such as during highsunlight conditions or the like.

Optionally, the viewability of the display may be enhanced by tintingthe vehicle windows to reduce the washout affect that may occur on sunnydays. Also, it is envisioned that the viewability of the display may beenhanced by enhancing the contrast at the display. Optionally, forexample, the mirror reflective element may be colored (such as slightlycolored or tinted) at the area in front of the display, in order toenhance or improve the contrast ratio of the display.

Because of the substantial power and heat generated by the super highintensity illumination source or LED array of the display module of thepresent invention, it is highly desirable to draw the heat away from thecircuitry and the LEDs to limit or avoid damage to the circuitry and/orLEDs due to the heat. Thus, one or more thermally conductive elements orheat sink slugs are placed in substantial and/or intimate thermalcontact with the display module and/or circuit board and are exposed atthe rear casing of the mirror so as to draw the heat away from thedisplay module and/or circuit board and to the exterior of the mirrorassembly, so as to dissipate and/or radiate the heat at the exterior ofthe mirror assembly.

In the illustrated embodiment, a thermally conductive element 616 islocated at and is in intimate contact with the display module 614 and athermally conductive element 617 is located at and is in intimatecontact with a portion of the circuit board 630, so as to conduct and/ordissipate heat generated by the display module 614 and the circuitry ofcircuit board 630, respectively. The thermally conductive elements 616,617 may comprise any suitable thermally conductive material, such as ametallic material or thermally conductive plastics or the like.Optionally, the thermally conductive material comprises a thermallyconductive polyphenylene sulfide (PPS), such as a COOLPOLY® E5101Thermally Conductive Polyphenylene Sulfide commercially available fromCool Polymers, Inc. of Warwick, R.I. The thermally conductive elements616, 617 are formed, such as via molding or the like, and positioned atthe rear of the mirror casing 620, such as at or within apertures oropenings 620 a, 620 b formed or established at the rear of the mirrorcasing 620. Although two separate thermally conductive elements areshown and described herein, it is envisioned that a single thermallyconductive element may be in intimate contact with both the displaymodule and the circuit board to dissipate the heat therefrom, or two ormore thermally conductive elements may be intimate contact with thedisplay module and/or the circuit board to dissipate the heat therefrom,while remaining within the spirit and scope of the present invention.

Preferably, the thermally conductive elements are molded, such as viainjection molding or the like, to the desired form so that a rear orexterior surface of the thermally conductive elements match orsubstantially match the exterior surface of the mirror casing at thearea where the thermally conductive elements are located. The thermallyconductive elements thus may be injection molded, and may be molded withselected or different pigments and/or materials to provide differentcolors and/or textures to substantially match the exterior surface ofthe mirror casing so as to be substantially not visible or discernibleto the consumer. Preferably, the thermally conductive material is loadedwith the likes of graphite or other suitable conductive materials forenhanced conductivity.

Optionally, the thermally conductive element or elements may comprise ametallic material, such as a magnesium material or other suitable heatsink material. For example, a magnesium alloy material such as MagnesiumAM40A-F or other suitable metallic material or metal alloy material maybe implemented to achieve the desired heat transfer and dissipation. Themetallic thermally conductive element or elements may be die cast (orotherwise formed) to the desired form and may be formed and contoured tosubstantially match the exterior surface of the mirror casing so as toreduce the discernibility of the thermally conductive element at themirror casing. Optionally, and desirably, the metallic thermallyconductive element may be painted or coated at its outside surface tocolor match the plastic of the mirror casing and thus at least partiallyor substantially covertly camouflage the presence of the thermallyconductive element at the exterior mirror casing. Optionally, themetallic thermally conductive element may be powder coated fordurability. Any exterior coating or paint layer or skin layer at theouter surface of the thermally conductive element preferably comprises athermally conductive material or paint as well so as to enhance the heattransfer and dissipation of the heat through the thermally conductiveelement and to the exterior of the mirror casing. Optionally, anddesirably, a plastic grating or vent-like structure or grill may atleast partially cover the outer surface of the heat sink or thermallyconductive element so that it is difficult for a person's hand to comein contact with the actual surface of the thermally conductive elementin order to reduce the possibility of a person experiencing discomfortif the person touches the thermally conductive element after the displayhas been activated and in use for a prolonged period of time. Such agrating or vent or grill allows for air flow and heat dissipation at theheat sink and also may shield or shadow the heat sink at or near thewindshield to reduce solar loading at the heat sink, such as mayotherwise occur on a sunny day.

The thermally conductive element or elements may be positioned at anaperture or apertures of the mirror casing, and may snapped into themirror casing, whereby the exterior surface of the thermally conductiveelement/elements match or substantially match the contour and/or textureand/or color of the mirror casing so that the thermally conductiveelements are not readily discernible by a person viewing the rear of themirror assembly. Optionally, the thermally conductive elements may beinsert molded at the mirror casing or otherwise attached at the mirrorcasing. The thermally conductive elements thus provide a heatconductivity function at the mirror casing, without being readilydiscernible at the rear of the mirror casing. Thus, the thermallyconductive elements may be located at an exterior surface or region ofthe mirror casing, yet are covertly camouflaged so that the thermallyconductive elements are not readily visible or discernible at the rearof the mirror casing. Optionally, a thin layer or skin may be moldedover the thermally conductive layer to provide an exterior surface layerthat substantially matches the Class A finish of the mirror casing. Thethin layer or skin may comprise a thermally conductive material toenhance heat transfer therethrough, while providing a thin,aesthetically pleasing outer layer or surface at the mirror casing.Thus, the exposure of the thermally conductive element at the rearcasing portion of the interior rearview mirror assembly is substantiallynot discernible to a viewer viewing the rear casing portion of theinterior rearview mirror assembly from outside of the vehicle andthrough the windshield of the vehicle when the interior rearview mirrorassembly is mounted at the vehicle, such as at a mounting button or thelike at the interior surface of the vehicle windshield. The presence ofthe thermally conductive elements is thus substantially or entirelycamouflaged and not readily discernible to a person viewing the mirrorcasing.

In applications where only one thermally conductive element is used orwhere no thermally conductive elements are used, one or more “blanks” orfilling elements may be used to fill in and cover/conceal the aperturesfor the thermally conductive elements. For example, a blank or fillingelement may be attached (such as via a snap attachment or the like) atthe aperture formed at the mirror casing if a thermally conductiveelement is not necessary (such as if a video display option was notselected for that mirror assembly). Thus, a common mirror casing may beused for mirrors with and without the video display feature or function,whereby either a thermally conductive element or a blank element isattached or located (or insert molded) at the casing depending on theparticular application.

As shown in FIGS. 32A, 32B, mirror casing 620 may include tab or clipelements 620 c that functions to snap and retain the thermallyconductive elements 616, 617 at the apertures 620 a, 620 b,respectively. The thermally conductive elements 616, 617 may be formedwith tabs 616 a, 617 a extending therefrom and recesses 616 b, 617 bformed or established thereon. Thus, the thermally conductive elements616, 617 may be positioned at the apertures 620 a, 620 b with the tabs616 a, 617 a located at corresponding recesses or portions 620 d ofcasing 620, and then pressed into the apertures, whereby the tabs 620 csnap or clasp the thermally conductive elements 616, 617 at the recesses616 b, 617 b to retain the thermally conductive elements at the rear ofthe mirror casing 620. Optionally, the mirror casing may utilize aspectsof the mirror casings and casing portions described in U.S. patentapplication Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No.7,249,860, which is hereby incorporated herein by reference in itsentirety. Optionally, the casing or a portion thereof may comprise athermally conductive material to conduct and dissipate heat from thedisplay module and/or circuit board to the exterior of the mirrorassembly.

In order to facilitate and provide substantial heat transfer from thedisplay module 614 and/or the circuit board 630, the module and circuitboard should be in intimate contact with the respective thermallyconductive elements 616, 617, and with minimal air pockets between thedisplay module and circuit board and the respective thermally conductiveelements. Thus, it is desirable to press the thermally conductiveelements to the display module and circuit board and to adhere theelements in position at the display module and/or circuit board. Forexample, and as shown in FIGS. 27 and 30D, thermally conductive element616 is adhered to a rear surface of display module 614 via adouble-sided adhesive thermal tape 632, which provides an intimateconnection between the display module and the thermally conductiveelement. The thermal tape (such as, for example, a thermal adhesive tapeof the type commercially available from 3M, such as a 3M 8820 tape or a3M 8810 tape or a 3M 8805 tape or other suitable adhesives or tapes) ispreferably substantially thermally conductive so that heat generated bythe display module 614 is conducted through the tape 632 and to thethermally conductive element 616, where the heat is dissipated at therear of the mirror casing and outside of the mirror to substantiallyreduce the operating temperature at the display module. Optionally, anddesirably, a compressible, resilient heat transfer pad 634 may beprovided between the thermally conductive element 616 and the displaymodule 614 to allow the components to be compressed together duringassembly, whereby they would remain in intimate contact with oneanother. The heat transfer pad may comprise any suitable thermallyconductive, compressible/resilient material, such as a solid orsubstantially solid or dense thermally conductive or filled siliconematerial or the like. Preferably, the tape and pad may comprise asuitable heat sink compound or the like to enhance the thermalconductivity between the display module and the thermally conductiveelement. The display module 614 may also or otherwise be compressible toaccommodate tolerances and to allow the thermally conductive element 616to be pressed firmly against the rear surface of the display module toensure intimate contact therewith, as discussed below.

In the illustrated embodiment, circuit board 630 comprises a multi-layercircuit board, such as a four layer PCB or the like. The circuit board630 thus has a primary substrate 630 a that supports circuitry and asecondary or tiered substrate 630 b that supports heat generatingcircuitry or the like at a location remote from the circuitry at theprimary substrate 630 a. The substrates may comprise a glass filledepoxy substrate or an aluminum substrate (with layer of non-conductivematerial over the substrate and with the copper traces disposed on thenon-conductive material) or other suitable materials or types ofsubstrates.

The secondary substrate 630 b is preferably movably attached to theprimary substrate 630 a to allow for movement of secondary substrate 630b toward from primary substrate 630 a as the thermally conductiveelement 617 is pressed firmly against the secondary substrate 630 b toensure intimate contact between the secondary substrate and thethermally conductive element 617. Similar to the connection betweenthermally conductive element 616 and display module 614, and as shown inFIGS. 27 and 30C, thermally conductive element 617 is pressed againstand held at a rear surface of secondary substrate 630 b of circuit board630 with a compressible, resilient heat transfer pad 634 providedbetween the thermally conductive element 617 and the secondary substrate630 b to allow the components to be compressed together during assembly,whereby they would remain in intimate contact with one another. The heattransfer pad may comprise any suitable thermally conductive,compressible/resilient material, such as a solid or substantially solidor dense thermally conductive or filled silicone material or the like.

Preferably, the secondary substrate 630 b is mounted to primarysubstrate 630 a via posts or legs 630 c (FIG. 30C) that allow formovement of secondary substrate 630 b toward primary substrate 630 a asthe thermally conductive element is pressed thereagainst. The substratesor legs may be biased so as to be biased toward an initial spaced apartconfiguration of the substrates to urge the secondary substrate towardand against the thermally conductive element 617. The circuitry of thesubstrates are electrically connected together and remain electricallyconnected during any such movement of the secondary substrate. Suchmovement of the secondary substrate during compression of the thermallyconductive element and circuit board accommodates tolerances and allowsthe thermally conductive element 617 to be pressed firmly against thecompressible heat transfer pad 634 and the rear surface of the secondarysubstrate 630 b to ensure intimate contact therewith.

Thus, the mirror assembly of the present invention provides for enhancedheat conductivity and dissipation from heat generating components withinthe mirror assembly to reduce the operating temperatures at thosecomponents within the mirror casing. The thermally conductive elementscomprise a thermally conductive material that conducts the heatgenerated by the mirror components or devices to draw the heat fromthose components or devices and to dissipate the heat at the rear of themirror and outside of the mirror casing. The thermally conductiveelements are pressed against the respective mirror components (such asthe display module and circuit board and/or the like) and are assuredgood thermal conductivity between the elements to reduce hot spots andto enhance the heat flow to allow the heat to escape through the mirrorcasing, such as through the back of the mirror casing. Optionally, themirror assembly may also or otherwise include a micro-fan or other airmoving device, which may be directed so as to move or blow the heatedair at the display module or circuit board so as to cool the areasurrounding the display module or circuit board, or so as to move orblow the air at the thermally conductive elements to enhance cooling andheat dissipation at the thermally conductive elements.

The thermally conductive elements may be molded or formed or contouredto substantially match or correspond to or be part of the mirror casing,and may be insert molded at the rear (or elsewhere if desired) of themirror casing. Optionally, the mirror casing may be formed of suchmaterials, but such a configuration is less desirable due to the effectsthe thermally conductive material may have on the surface finish,weight, cost and functionality of the casing. Optionally, the thermallyconductive elements may be painted or textured or coated or otherwisefinished at the rear surface thereof in order to substantially match thecolor or texture or appearance of the mirror casing, so that thethermally conductive elements are not readily discernible by a personviewing the rear of the mirror assembly. Optionally, the mirror casingmay be formed with ribs or raised portions or grating or vents orbaffles or louvers or vanes across the apertures (such as a plurality ofspaced apart ribs over or across the aperture), whereby the ribs coverparts of the outer or rear surface of the thermally conductive elementsto limit or reduce the possibility of a person directly touching thethermally conductive elements in the event that they may increase intemperature during operation of the display module or circuitry of themirror assembly, and/or to shade the thermally conductive elements toreduce solar loading thereof, and/or to further dissipate the heat thatis dissipated by the thermally conductive element or elements.Preferably, the thermally conductive element or elements can be insertmolded at or snapped to the mirror casing. In applications where thethermally conductive element or elements is/are not used, a blank orfiller element may be attached or insert molded at the mirror casing.

Optionally, the mirror casing may include ribs or grating or vents orbaffles at the region of the casing that is generally at the thermallyconductive element or elements when the mirror assembly is assembled, inorder to substantially conceal the thermally conductive element and/orto limit or substantially preclude a person touching the thermallyconductive element and/or to reduce solar loading of the thermallyconductive element, such as may otherwise occur on a sunny day.Optionally, for example, and with reference to FIG. 42, a thermallyconductive element 616′ is disposed between the video display module 614and the rear mirror casing or housing 620′, which has or vents orgrating 620 a′ at the area or region that generally corresponds tothermally conductive element 616′ when the mirror is assembled. Thethermally conductive element may comprise any suitable thermallyconductive element, such as described above. Optionally, and in theillustrated embodiment of FIG. 42, thermally conductive element 616′ maycomprise a plastic molded heat dissipating element or heat sink, such asa cool polymer heat sink or the like. The molded thermally conductiveelement is disposed between and in intimate contact with the rear of thedisplay module (such as at an aluminum clad circuit board with LEDsdisposed thereat that forms the rear of the display module), and may beadhered at or to the rear of the display module via an adhesive, such asa thermal tape 632 or the like. The mirror casing 620′ and/or thermallyconductive element 616′ may otherwise be substantially similar to themirror casings and/or thermally conductive elements described above andbelow, such that a detailed discussion of the mirror casing andthermally conductive elements need not be repeated herein.

Optionally, for example, and with reference to FIG. 43, the thermallyconductive element 616″ may be formed to include a body portion 616 a″with ribs or protrusions 616 b″ protruding at its rear surface so as tobe toward or against the grating 620 a′ of mirror casing 620′ when themirror is assembled. The protrusions protrude a desired or appropriatedistance from the body of the thermally conductive element so as to beat or in contact with the grating 620 a′ of mirror casing 620′ when themirror is assembled. As can be seen in FIG. 43, the protrusions 616 b″may be different lengths to correspond to a curve or form of the mirrorcasing. The thermally conductive element 616″ may comprise an extrudedaluminum heat sink or an extruded anodized heat sink or other suitablematerial, and is in intimate contact with and/or adhered to the rear ofthe display module 614, such as via a thermal tape 632 or the like. Thethermally conductive element 616″ may otherwise be substantially similarto the thermally conductive elements described above and below, suchthat a detailed discussion of the thermally conductive elements need notbe repeated herein.

Optionally, for example, and with reference to FIG. 44, the thermallyconductive element 616′″ may be integrally formed at the rear of thevideo module 614′, so as to be at the grating or vents 620 a′ of mirrorcasing 620′ when the mirror is assembled. For example, thermallyconductive element 616′″ may comprise a substrate 648′ (such as anextruded substrate, and such as a substrate similar to substrate 648discussed below) with LEDs and circuitry (not shown in FIG. 44) disposedat or established at one side of the substrate and a plurality of finsor protrusions 616 b′″ protruding from the opposite side of thesubstrate so as to protrude/extend toward the vents 620 a′ of mirrorcasing 620′ when the mirror is assembled. Such an application obviatesthe need for the thermal tape at the rear of the video module byestablishing or integrally forming the heat sink or thermally conductiveelement at the rear of the video module. The protrusions or fins 616 b′″protrude a desired or appropriate distance from the body of thethermally conductive element so as to be at or in contact with thegrating 620 a′ of mirror casing 620′ when the mirror is assembled. Ascan be seen in FIG. 44, the protrusions 616 b′″ may be different lengthsto correspond to a curve or form of the mirror casing. The thermallyconductive element 616′″ may otherwise be substantially similar to thethermally conductive elements described above and below, such that adetailed discussion of the thermally conductive elements need not berepeated herein.

In the illustrated embodiment, and with reference to FIGS. 33-38, thedisplay module 614 comprises a backlit liquid crystal display modulehaving a liquid crystal display screen 624 (such as a TFT LCD screen orthe like, such as described above) and an illumination source 640disposed behind the display screen 624 and operable to emit or projectillumination toward and through the display screen. The display screen624 and illumination source 640 are disposed within or encased or cladwithin an outer casing or housing 642 of the module 614. The casing orhousing 642 (such as an aluminum housing or housing made of othersuitable material such as FR-4 or the like) substantially encases theillumination source 640 and display screen 624 and associated circuitry644 of the display device so as to provide a self-contained aluminumclad (or other material) video display screen module for use with amirror assembly. The display module may comprise a known or commerciallyavailable display module, which may provide reduced costs due toeconomies of scale in using an off-the-shelf, commercially availabledisplay module.

Optionally, the display module may be developed and constructedparticularly for use in a vehicle mirror assembly. For example, thedisplay module casing 642 may support and/or substantially encase theillumination source 640 and video screen 624, and may support orsubstantially encase circuitry 644 of the display module 614. Thecircuitry 644 functions to control the display screen and theillumination source (such as in response to or in conjunction with imagedata and/or a user input or the like), and is electrically connected toa connector or lead 644 a that protrudes from the casing 642 forconnection to the circuitry of the mirror assembly and/or vehicle.Optionally, the circuitry of the display module may also function toprovide dimming control of the electrochromic reflective element, whileremaining within the spirit and scope of the present invention. In theillustrated embodiment, the illumination source 640 of the displaymodule comprises a plurality of light emitting diodes 646 (LEDs), suchas a plurality of high intensity white LEDs disposed behind the displayscreen and operable to emit light directly toward the display screen toprovide direct back lighting of the display screen.

For example, and as described above, the illumination source 640 maycomprise sixty-four white LEDs 646 arranged in a matrix on a substrate648 at the rear of the housing 642. The LEDs 646 may be electricallyoperated as two banks of LEDs, with each bank including thirty-two LEDs,and with the LEDs being operated in groups of two or pairs, with theLEDs of each group of two being operated in series. The pairs of LEDsmay be operated by applying 8.5 V across the pair at a current of about20 mA. The current may be applied via a pulse width modulation (PWM) andwith the peak currents of each bank of LEDs being staggered so that thecurrents are applied at slightly different times to reduce or spread outthe electromagnetic emissions. It is desirable to apply a substantiallyconstant current to the LEDs to limit or substantially preclude colorshifts in the LED outputs. It is envisioned that more than two LEDscould be operated in series, but if a series fails, additional LEDswould be deactivated with such a configuration. Also, additional LEDs inthe series of LEDs may require additional power supplies to step thevoltage up to provide enough voltage to drive the multiple LEDs inseries. Thus, pairs of LEDs are desired to reduce costs and maintain therequired current as low as possible. However, other quantities of LEDsor light sources and/or other groups or pairings of more or less LEDs orlight sources may be operated or controlled in other manners, whileremaining within the spirit and scope of the present invention.Optionally, the intensities of the LEDs or light sources may be adjustedor controlled in response to one or more photosensors (so as to, forexample, decrease the intensity of the illumination source at dusk orother low or reduced lighting conditions), such as in response to aforward facing photosensor 649 a (FIGS. 28 and 40) and a rearward facingphotosensor 649 b (FIGS. 29 and 40) at the mirror assembly or such as inresponse to other photosensors located elsewhere at or in the vehicle.

Optionally, and desirably, and as best shown in FIGS. 34-37, displaymodule 614 may include a reflective layer or reflector 650 at the LEDs646 (such as LEDs of the types described in U.S. patent application Ser.No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381, whichis hereby incorporated herein by reference in its entirety), withapertures formed through the reflector 650 for light emitted by the LEDsto pass therethrough. The LEDs 646 thus emit light through the reflector650 to and through the video screen 624. However, some of the lightemitted by the LEDs will reflect back off of the rear surface of thedisplay screen and back generally toward the LEDs. The reflector 650preferably comprise a highly reflective (such as specular reflectivityor diffuse reflectivity of at least about 50 percent reflectance oflight incident thereon, more preferably at least about 70 percentreflectance of light incident thereon, and more preferably at leastabout 90 percent reflectance of light incident thereon) surface thatreflects the reflected light back toward the video screen 624 so thatmore of the light emitted by the LEDs is used to back light the videoscreen. For example, the reflector 650 may comprise an aluminumreflector or other suitable reflective material, and may comprise astamped metallic sheet or layer (and may function as a heat sink orpartial heat sink as well) with the apertures stamped or punchedtherethrough. The reflector 650 may be located so as to be intimate withor just above the LEDs so that it is generally at the plane of the LEDsat which the light is emitted (to minimize or substantially precludelight emitted by the LEDs from reflecting off the rear surface of thereflector and back toward the substrate 648). Optionally, the insidesurfaces of the walls 652, 653 defining the LED cavity may also behighly reflective, and could be coated plastic walls or could bemetallic to establish the desired degree of reflectivity at thesidewalls of the LED cavity.

Display module 614 may comprise a compressible display module that iscompressible when assembled in the mirror assembly to provide a snug fitand intimate contact with the thermally conductive element 616. Forexample, and as best shown in FIGS. 34-37, display module 614 mayinclude compressible elements, such as compressible walls 652, 653, thatallow for compression of the display module. An upper or forward wall652 supports the video screen 624 at an upper or outer end 652 athereof, while a lower or rearward wall 653 supports the illuminationsource 640 at a lower or rearward end 653 a thereof. In the illustratedembodiment, the walls 652, 653 engage one another and overlap at agenerally central region, and are correspondingly stepped at theirengaging/overlapping surfaces to allow for movement in one direction(such as vertically in FIGS. 34-37, but forwardly and rearwardly whenthe display module is located at an interior rearview mirror of avehicle), while substantially precluding lateral movement of the upperwall 652 relative to the lower wall 653. A compressible or resilientelement or gasket 654 is disposed between the upper and lower walls 652,653 and is compressible when the upper wall 652 is moved or compressedtoward the lower wall 653. The resilient element 654 may comprise aresilient material, such as a foam or foam rubber or the like.

The upper and lower walls 652, 653 thus may be compressed toward oneanother during installation of the display module 614 in the mirrorassembly 610, and thus may accommodate for variations in dimensions andtolerances of the components while allowing for snug and intimatecontact between the rear surface of the display module 614 and thethermally conductive element 616 (and/or the thermally conductive tapeand/or thermal pad disposed between the display module and the thermallyconductive element). The foam or resilient material may at leastinitially urge the lower wall 653 away from the upper wall 652 to urgethe rear of the display module into intimate contact with the thermallyconductive element 616 (but may lose or reduce the biasing over timewithout affecting the intimate contact, since the thermally conductiveelement 616 is adhered to the rear of the display module via the thermaltape 632).

Thus, when the display module 614 and thermally conductive element 616are installed or positioned at and in the mirror during assembly of themirror, and the bezel and mirror casing and other components areassembled together, the components may be compressed together and biasedinto efficient thermal contact, with the display module absorbing oraccommodating the compression to reduce the pressure at the displaymodule and video screen. The display module and the thermally conductiveelement thus may be pressed into intimate contact with one another toreduce or substantially preclude any air pockets or gaps therebetween,so as to provide enhanced thermal conductivity from the display moduleto the thermally conductive element, and without excessive forces at thedisplay screen. The mirror assembly may secured together with thedisplay module in the compressed or partially compressed state and thecomponents may be heat staked together (or otherwise secured, such asvia ultrasonic welding or the like) to ensure the compression andthermal conductivity between the components.

In the illustrated embodiment, display screen 624 is supported at arecess 652 b established or formed at the forward end of wall 652. Asshown in FIG. 35, the display screen 624 comprises a liquid crystaldisplay and may include a diffuser 625 adhered or attached or disposedat a rear surface of the liquid crystal display screen 624. Otherdisplay enhancing elements or sheets or optical layers or elements, suchas a polarizer or polarizing element 658, may be located at the displayscreen to enhance the appearance of the display screen during operationthereof.

As best shown in FIGS. 38A and 38B, display screen 624 may be supportedand retained at recess 652 b of wall 652 via a plurality of flexiblesupport beams or arms or elements 656. In the illustrated embodiment,flexible support elements 656 include a plurality of projections orfingers 656 a that extend laterally to engage the perimeter edges of thedisplay screen so as to support and locate the display screen at theforward end of the wall 652 and display module 614. Flexible supportelements 656 extend at least partially along an outer wall portion 652 cof recess 652 b and may flex laterally (such as at recesses or openingsor gaps 652 d at the outer wall portion 652 c that correspond generallyto the location of the fingers 656 a of flexible support elements 656)to locate the display screen at the appropriate location and to providesupport of the display screen at the wall 652 of display module 614.

Thus, the display screen 624 may be located at the forward or outer endof the wall 652 of display module 614 and retained in the desired orappropriate location via the fingers 656 a of flexible support elements656. The flexible support elements and spring fingers thus mayaccurately support and locate the display screen within the plastic wallof the display module. The flexible support elements 656 may flex ordeflect during contraction of the plastic wall (such as may occur duringtemperature changes encountered by the vehicle and/or display module) soas to retain the display screen (and particularly the active area of thedisplay screen) at the appropriate location relative to the mechanics ofthe display module during such contraction of the wall itself, whilelimiting or reducing the stresses applied to the display screen duringsuch contraction of the plastic wall. Other forms of spring clips orelements that may flex to allow for contraction of the plastic wallwhile reducing stresses on the display screen may be implemented whileremaining within the spirit and scope of the present invention.

The walls 652, 653, illumination source 640 and display screen 624 andcircuitry 644 are substantially encased within housing 642, which mayhave a thermally conductive adhesive tape 632 applied at its rearsurface for attachment/adhesion to thermally conductive element 616. Forexample, the adhesive tape 632 may be adhered or disposed at the rearsurface of the housing 642 and may have a peel away backing membranethat is peeled away from the adhesive to expose the adhesive prior toadhering the thermally conductive element 616 to the display module 614.Likewise, an adhesive tape 643 may be disposed at or adhered to aforward surface of the display module (and may have a peel away backingto selectively expose the tape) for attaching or adhering the displaymodule to the masking element 622 and/or rear surface of the reflectiveelement 612.

The display module and display screen are located at the rear of thereflective element and may be at the window or aperture through theopaque layer or masking element, so that the active area of the displayscreen is viewable through the reflective element when the displayscreen and illumination sources are activated, and with the displayscreen and display module being substantially not visible or discerniblewhen the display screen and illumination sources are deactivated. Forexample, and with reference to FIG. 39A, the display module 614(including the display screen 624, backlighting element 640 and forwardor front-most polarizer 658) may be disposed at the aperture 622 a ofmasking element 622 and at the rear of the reflective element 612. Thepolarizer 658 and display screen 624 and backlighting element orillumination source 640 may overlap or extend over the masking element622 so that the perimeter edge or edges of the display module and/ordisplay screen are not visible to a person viewing the reflectiveelement 612, such that the presence of the display screen and module iscovertly camouflaged. The thermally conductive element 616 is disposedat the rear of the display module and in intimate contact therewith(such as via a thermal adhesive and/or thermal pad or the like) and islocated at the aperture 620 a at the rear of the mirror casing 620, suchthat the exterior surface of the thermally conductive element 616 is atand preferably substantially matches the contour of the exterior surfaceof the mirror casing, such as described above.

In the illustrated embodiment, the reflective element 612 comprises atransflective reflective element or cell having a front substrate 612 awith a transparent conductor 612 b (such as a transparent conductorlayer comprising an indium tin oxide (ITO) or an AZO layer or the like)at its rear surface (commonly referred to as the second surface of thereflective element), and a rear substrate 612 c with a transflectivemirror reflector 612 d at its front surface (commonly referred to as thethird surface of the reflective element), and with an electro-opticmedium 612 e (such as an electrochromic medium) disposed therebetweenand sealed via a perimeter seal 612 f. The reflective element mayutilize aspects of the electro-optic or electrochromic mirror assembliesdescribed in U.S. Pat. Nos. 6,690,268; 5,668,663; 5,142,406; 5,442,478and 5,724,187, and/or in U.S. patent application Ser. No. 10/054,633,filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381; Ser. No. 11/021,065,filed Dec. 23, 2004, now U.S. Pat. No. 7,255,451; Ser. No. 10/528,269,filed Mar. 17, 2005, now U.S. Pat. No. 7,274,501; Ser. No. 10/533,762,filed May 4, 2005, now U.S. Pat. No. 7,184,190; Ser. No. 10/538,724,filed Jun. 13, 2005 and published Mar. 9, 2006 as U.S. Publication No.US-2006-0050018; Ser. No. 11/226,628, filed Sep. 14, 2005 and publishedMar. 23, 2006 as U.S. Publication No. US-2006-0061008; Ser. No.10/993,302, filed Nov. 19, 2004, now U.S. Pat. No. 7,338,177; and/orSer. No. 11/284,543, filed Nov. 22, 2005, now U.S. Pat. No. 7,370,983;and/or PCT Application No. PCT/US2006/018567, filed May 15, 2006 andpublished Nov. 23, 2006 as International Publication No. WO 2006/124682,which are all hereby incorporated herein by reference in theirentireties. Other reflective elements or reflective elementconfigurations or arrangements may be implemented without affecting thescope of the present invention.

Optionally, and with reference to FIG. 39B, the polarizer 658′ may bedisposed over substantially the entire rear surface of the rearsubstrate 612 c of reflective element 612, with the light absorbingsubstantially opaque layer or masking element 622 disposed over thepolarizer 658′ except at the window area 622 a. The display screen 624and backlighting element 640 of display module 612 are located at thewindow area 622 a and at the polarizer 658′, whereby the display screenis located behind the polarizer, and the display screen and theperimeter edges thereof are not readily discernible when the displayscreen and backlighting element are deactivated.

Optionally, and with reference to FIG. 39C, the polarizer 658″ may bedisposed at the display area at rear surface of the reflective element,and the light absorbing substantially opaque layer 622′ may be disposedpartially over the perimeter regions of the polarizer 658″. The displayscreen 624 and backlighting element 640 of display module 612 arelocated at the window area 622 a′ of the opaque layer 622′ and at thepolarizer 658″, whereby the display screen is located behind thepolarizer, and the display screen and the perimeter edges thereof arenot readily discernible when the display screen and backlighting elementare deactivated.

Optionally, other configurations or arrangements of the display moduleand polarizer and opaque layer may be implemented at the rear of thereflective element, depending on the particular application and desiredappearance of the mirror assembly. For example, and with reference toFIG. 39D, the housing 642 has an opening or aperture 642 a formed orestablished at its forward surface that is sized so as to frame theactive area of the video screen 624. The aperture 642 a of housing 642may be sized so as to be greater than the window 622 a established bymasking element 622. Polarizing element 658 may be at the forwardsurface of the display screen or LCD 624 and the polarizing element 658and display screen 624 are sized so as to be greater than the aperture642 a of housing 642, with an active area 624 a of the display screenbeing smaller than the window 622 a of masking element 622. Thus, theactive area of the display screen is viewable through the reflectiveelement 612 and at the window 622 a and, because the masking element 622is selected to substantially match the appearance of the polarizer 658,the display screen is substantially non-discernible when the displayscreen is deactivated or non-illuminated.

Optionally, and with reference to FIG. 39E, the display screen 624 maybe attached to a rear or inner surface of a glass substrate 660, with apolarizer 658′″ attached at the outer surface of the glass substrate660. The glass substrate 660 provides a mounting structure to extend themounting area of the display screen so that the display screen may bemounted or located at a larger sized aperture or window if desired,while still limiting viewability or discernibility of the display screenwhen it is not illuminated or backlit. Optionally, and with reference toFIG. 39F, aperture 642 a in housing 642 may be smaller than the apertureor window 622 a of the masking element 622, with the display screen 624and polarizer 658 attached or located at the aperture 642 a so that theactive area 624 a of the display screen is viewable through thereflective element 612 and windows 622 a, 642 a. In such an application,the housing 642 preferably has an outer surface that substantiallymatches the color and/or appearance of the masking element and polarizerso that it is substantially non-discernible by a person viewing thereflective element. For example, the housing may be painted or otherwisecolored or coated or treated so as to provide a dark or opaque surfacethat is substantially non-discernible when positioned at and behind themasking element and partially overlapping the window 622 a of themasking element 622. Optionally, the forward portion or surface of thehousing may incorporate or comprise a piece of metal shim stock (such asdescribed in PCT Application No. PCT/US2006/018567, filed May 15, 2006and published Nov. 23, 2006 as International Publication No. WO2006/124682, which is hereby incorporated herein by reference in itsentirety) that has a window formed or laser cut therefrom that matchesor substantially matches the size and shape of the active area of thedisplay screen.

As shown in FIGS. 34, 35 and 37, the outer housing 642 may trap andcontain the display screen 624 and optical films (such as polarizer 658and diffuser 625) at the forward end portion of the display module.Optionally, and desirably, a thin sponge-like material or element 662may be located at the perimeter edge of the display screen to hold theedge of the display screen in slight compression at the housing andbetween the forward portion of the housing and the forward portion ofthe wall 652 at recess 652 b of wall 652.

With reference to FIG. 40, a control system 664 may be implemented tocontrol the display module 614. Desirably, the control system 664 maycontrol the display screen to display video images in response to anoutput of one or more video cameras 666 of the vehicle, such as arearwardly facing video camera operable to capture images at the rear ofthe vehicle. Preferably, the display module 614 is operable inconjunction with a reverse imaging system or back up aid, and thecontrol system may operate to activate the display module 614 and thecamera or imaging device 666 in response to the vehicle being shiftedinto a reverse gear or in response to rearward movement of the vehicleor the like. Thus, the display module may be activated to display imagesof a rearward scene behind the vehicle, and may be viewable when thedriver of the vehicle is reversing or backing up the vehicle.Optionally, the display module may be selectively operable and viewablefor other applications or systems, such as for episodal or episodicdisplays or intermittent/selective displays, such as for a navigationsystem or compass system or telephone system or the like, such asdescribed above, while remaining within the spirit and scope of thepresent invention.

As shown in FIG. 40, the display module 614 includes two banks of LEDs646, a constant current LED driver 668 for each bank of LEDs, and avoltage regulator 670 to step down or reduce the supplied voltage to thedesired or appropriate level for powering the LCD video screen 624 andthe LEDs 646. The control system 664 includes a controller ormicrocontroller 672 (such as, for example, a Toshiba MicrocontrollerTMP86CM47 or the like) that is operable to apply the staggered pulsewidth modulation signals 672 a to the constant current LED drivers 668,and that may be operable in response to the forward and rearward facingphotosensors 649 a, 649 b (such as Microsemi LX1973 photosensors or thelike, such as described in PCT Application No. PCT/US2006/018567, filedMay 15, 2006 and published Nov. 23, 2006 as International PublicationNo. WO 2006/124682, which is hereby incorporated herein by reference inits entirety) and a reverse inhibit element 674. The control system 664also includes a video decoder 676 (such as an ADI Video DecoderADV7180BCPZ or the like) and a scalar 678 (such as a Novatek ScalarNT68521XFG or the like) and a controller or microcontroller 680 (such asa Micro Chip Micro Controller PIC12F629 or the like) for controlling theLCD video screen 624 (which may comprise a Chi Mei TFT LCD F02505-01Uvideo screen or the like), such as in response to a feed from the camera666 (such as a Sony NTSC video camera or the like). Other components andcontrollers and circuitry may be suitable for use with the displaymodule and control system while remaining within the spirit and scope ofthe present invention.

Optionally, the display module may be located at the rear of thereflective element via a locating device that may accurately andrepeatedly place the display module at the masking element with theactive area of the display screen at the window or aperture of themasking element. For example, and with reference to FIGS. 41A-C, anassembly fixture 670 may have a base portion 670 a and a pivotableportion 670 b that functions to hold a display module and to pivot abouta pivot axis 670 c (which is substantially parallel to the plane of therear surface of the mirror reflective element and/or masking element).The base portion 670 a of assembly fixture 670 may receive thereflective element or bezel portion of the mirror assembly so that thedisplay modules held and pivoted/placed by the pivotable portion 670 bconsistently place the display modules at the desired or appropriate ortargeted location at the rear of the reflective element. The assemblyfixture 670 thus pivots to locate the display module at the reflectiveelement or masking element and moves the display module generally normalto the masking element when attaching or adhering the display module tothe masking element. Thus, the display module or the masking element mayhave a double-sided adhesive or tape thereon, whereby the substantiallyvertical or perpendicular movement of the display element at the maskingplate attaches the display module to the masking element and at thedesired or appropriate location relative to the window or display areaof the reflective element.

Therefore, the display module of the present invention is positionableand compressible within a mirror assembly and is in intimate contactwith a thermally conductive element so as to allow for heat flow fromthe display module to the rear and exterior of the mirror assembly. Thedisplay module includes a plurality of light sources or light emittingdiodes, whereby such heat transfer is highly desirable for such anapplication. The display screen, and particularly the active area of thedisplay screen, may be readily positioned at the appropriate locationfor viewing, and may be substantially retained thereat via flexiblespring-like fingers that substantially hold the display screen inposition during expansion/contraction of the plastic walls of thedisplay module while reducing stress at the perimeter edges of thedisplay screen. Although shown and described as being part of aninterior rearview mirror of a vehicle, it is envisioned that the displaymodule and/or thermally conductive elements of the present invention maybe equally suitable for use in exterior rearview mirror assemblies,while remaining within the spirit and scope of the present invention.

Optionally, the display module may be operable to display video imagesindicative of an exterior scene as captured by one or more exteriorlydirected imaging sensors or cameras having exterior and/or rearwardfield of views. It has long been known to use a standard short-range (30feet or thereabouts) wireless data communication protocol in vehicles(and/or communication protocols of the types described in U.S. Pat. Nos.7,004,593; 6,690,268 and 6,329,925, which are hereby incorporated hereinby reference in their entireties) for wireless connectivity in vehicles.Prior suggested solutions, such as conventional Bluetooth 2.0 that movesdata at only a mere 721 Kbps, work well for text and voicecommunication, but are overly slow for transmission of video images.Bluetooth 3.0 available from the Bluetooth Special Interest Group uses awireless protocol to operate at similar distances (around 30 feet or so)as today's Bluetooth 2.0, but transmits and receives data at a muchfaster rate, being capable of wireless transfers at a rate of 480 Mbps(megabits per second). This equates to about 60 MB per second (60megabytes per second) which is fast enough for high definition videotransfer, such as between a rear-mounted camera and a videocontrol/display in the interior cabin (such as at or in the interiormirror assembly), or between video cameras/devices in either or both ofthe exterior sideview mirror assemblies.

Thus, a video camera may be mounted or located at a rear portion of avehicle and may capture video images of a scene occurring exteriorly andrearwardly of the vehicle and the image data may be communicatedwirelessly to an image processor located remotely from the rear of thevehicle, such as at an interior rearview mirror assembly of the vehicle.The image processor may process the image data to detect objects in thescene to assist the driver in safely reversing or backing up thevehicle. The image processor may be an existing processor that islocated at or near the interior rearview mirror for processing imagescaptured from an existing forward facing imaging sensor or camera with aforward field of view. For example, the image processor and forwardfacing camera may be part of or operable in conjunction with a headlampcontrol (IHC) system or a rain sensing system or a lane departurewarning (LDW) system or a traffic sign recognition (TSR) system (such asthe types described in U.S. Pat. No. 7,004,606) or the like. Forexample, the image processor may comprise an EyeQ™ image processing chipavailable from Mobileye Vision Technologies Ltd. of Jerusalem, Israel.Such image processors include object detection software (such as thetypes described in U.S. patent application Ser. No. 10/427,051, filedApr. 30, 2003, now U.S. Pat. No. 7,038,577; and/or Ser. No. 11/315,675,filed Dec. 22, 2005 by Higgins-Luthman for OBJECT DETECTION SYSTEM FORVEHICLE, now U.S. Pat. No. 7,720,580, which is hereby incorporatedherein by reference in its entirety), and analyzes image data to detectobjects.

As disclosed in U.S. patent application Ser. No. 11/315,675, filed Dec.22, 2005 by Higgins-Luthman for OBJECT DETECTION SYSTEM FOR VEHICLE(U.S. Pat. No. 7,720,580), incorporated above, the present inventionprovides an object detection system, such as a blind spot detectionsystem, a lane change assist or aid system or device, a lane departurewarning system, a side object detection system, a reverse park aidsystem, a forward park aid system, a forward, sideward or rearwardcollision avoidance system, an adaptive cruise control system, a passivesteering system or the like, which is operable to detect and/or identifya vehicle or other object of interest at the side, front or rear of thevehicle equipped with the object detection system. The object detectionsystem of the present invention, such as for a lane change assistsystem, utilizes an edge detection algorithm to detect edges of objectsin the captured images and determines if a vehicle is present in a laneadjacent to the equipped or subject vehicle in response to variouscharacteristics of the detected edges, such as the size, location,distance, intensity, relative speed and/or the like. The systemprocesses a subset of the image data captured which is representative ofa target zone or area of interest of the scene within the field of viewof the imaging system where a vehicle or object of interest is likely tobe present. The system processes the detected edges within the imagedata subset to determine if they correspond with physicalcharacteristics of vehicles and other objects to determine whether thedetected edge or edges is/are part of a vehicle or a significant edge orobject at or toward the subject vehicle. The system utilizes variousfiltering mechanisms, such as algorithms executed in software by asystem microprocessor, to substantially eliminate or substantiallyignore edges or pixels that are not or cannot be indicative of a vehicleor significant object to reduce the processing requirements and toreduce the possibility of false positive signals.

The object detection system of the present invention may capture imagesat a side of the vehicle and may process various windows of the imagesto detect a vehicle in the adjacent lane or other object, such as abicycle, in the adjacent lane. The system may adjust the imageprocessing to account for misalignment of the camera at the side of thevehicle. The system may adjust the area or zone of interest in responseto a turning of the vehicle's wheels, such as when the vehicle isturning or curving along a curve in the road. The system may distinguishbetween vehicles or other objects and shadows of objects/vehicles sothat a shadow of a vehicle two lanes over may not be considered avehicle in the adjacent lane. The system may switch between daytime andnighttime algorithms and may be operable to detect headlamps of vehiclesin the adjacent lane.

According to an aspect of the present invention, an imaging system for avehicle includes an imaging array sensor and a control. The image arraysensor comprises a plurality of photo-sensing pixels and is positionedat the vehicle with a field of view exteriorly of the vehicle. Theimaging array sensor is operable to capture an image of a sceneoccurring exteriorly of the vehicle. The captured image comprises animage data set representative of the exterior scene. The controlalgorithmically processes the image data set to a reduced image data setof the image data set. The control processes the reduced image data setto extract information from the reduced image data set. The controlselects the reduced image data set based on a steering angle of thevehicle.

Optionally, the control may process the reduced image data set with anedge detection algorithm to extract information from the reduced imagedata set. The image sensor may be one of (a) part of an exteriorrearview mirror assembly of the vehicle and with a field of view atleast partially sideward of the vehicle, and (b) at an upper windshieldarea and behind the windshield of the vehicle and with a field of viewforward and through the windshield (such as at an area that is cleanedby the windshield wiper or wipers of the vehicle when the windshieldwipers are activated). Optionally, the image sensor may be part of anexterior rearview mirror assembly of the vehicle and with a field ofview at least partially sideward of the vehicle, wherein the imagingsystem comprises a side object detection system for detecting objects ata side of the vehicle. Optionally, the image sensor may be at an upperwindshield area and behind the windshield of the vehicle and with afield of view forward and through the windshield, wherein the imagingsystem comprises a lane departure warning system.

Therefore, the present invention provides an imaging system for use asor in association with a side object detection system and/or a lanedeparture warning system. The system is operable to process capturedimage data occurring exteriorly and along one or both sides of thevehicle to determine if a target vehicle or object of interest islocated at or in the lane adjacent to the subject or host vehicle. Theimaging system of the present invention may process zones or areas ofinterest in the captured images and may adjust processing to accommodateany misalignment of the camera that may occur during installation of thecamera at the side of the vehicle. The side object detection system mayalso select or adjust the image processing to select/adjust the areas ofinterest, such as in response to a steering angle of the vehicle, suchas a turning of the wheels of the vehicle, so that the zone or area isadapted for the turning of the subject vehicle. The imaging system ofthe present invention thus provides enhanced processing of capturedimages to provide the desired function of the imaging system orassociated control or control system or alert system.

When such an image processor and forward facing camera are provided in avehicle, such as at an interior rearview mirror assembly or windshieldelectronics module or accessory module or the like, the image processorand forward facing camera may not be utilized when the vehicle isshifted into reverse and/or traveling in reverse. Thus, the imageprocessor can be operable to multi-task and receive and process a videofeed from a rearward facing video camera to display the rearward sceneand/or to detect objects in the rearward scene. While such a processormay be implemented at the rearward facing camera, it is efficient andless costly to implement a single processor at either the forward orrearward facing camera (and preferably at the forward facing camera ator near the interior rearview mirror assembly or accessory module wherethe video display may be located) and to thus use only one processor forprocessing image data from both cameras.

For example, and with reference to FIG. 45, a wireless communicationsystem or imaging and display 710 may include an imaging sensor orcamera 714 at a rear portion 712 a of a vehicle 712 and an image displaydevice 716, such as a control/display device located at an interiorrearview mirror 718 a of the vehicle, whereby image data captured by therear camera 714 is communicated to the image display device 716 via asuitable wireless protocol. Optionally, the driver side exteriorrearview mirror 718 b and/or the passenger side exterior rearview mirror718 c may also or otherwise include or be associated with a respectiveside mounted imaging sensor or camera 720, 722, which is/are operable tocommunicate image data to the display device 716 via a suitable wirelessprotocol.

Preferably, for such wireless intra-vehicle video transfers, anultra-wideband (UWB) common radio platform that enables high-speed (480Mbps and beyond), low power consumption multimedia data transfers in awireless personal area network (WPAN) is utilized (such as is availablefrom the WiMedia™ Alliance). For example, the WiMedia UWB common radioplatform that incorporates media access control (MAC) layer and physical(PHY) layer specifications based on multiband orthogonalfrequency-division multiplexing (MB-OFDM) can be used for wireless videotransmission within the vehicle (or between the vehicle with road signsand the like, or for vehicle-to-vehicle communication). ECMA-368 andECMA-369 are international ISO-based specifications for the WiMedia UWBcommon radio platform.

For example, for a rearward facing imaging sensor or camera, the display(which may be located at or in a DoD™ transflective EC video mirror asdescribed above) may display information that may be desirable to adriver during the act of reversing the vehicle. For example, when thevehicle is shifted into a reverse gear, the processor may receive andprocess image data from the rearward facing camera and a rear videoscene with graphic overlays may be displayed on video display screen.Optionally, the distance to an object displayed on the screen may bedetected via ultrasonic sensing. Optionally, an alert may becommunicated to the driver of the vehicle if a child or object is in thefield of view of the camera and is in danger of being hit by the vehicleas the vehicle travels rearward (for example, a visual overlay or promptmay be displayed at the video screen initially, and an audible signalmay be communicated if a greater or threshold danger condition isdetected. Optionally, a Park Assist™ graphic overlay may be provided atthe display screen to assist the driver in parking the vehicle.Automatic braking of the vehicle may be provided for situations wherethe driver of the vehicle may not react to imminent danger of impactwith a detected child or object at the rear of the vehicle.

In situations when the vehicle is not placed in reverse, the processormay receive and process image data from a forward facing video cameraand/or the video display module at the mirror may display otherinformation, such as telephone information and/or compass informationand/or temperature information and/or navigation information, such aspoint-to-point navigation or the like, such as described above.Optionally, and for a forward or front facing imaging device or camera,the mirror assembly and/or control system of the vehicle may provide anintelligent headlamp control system (IHC) and/or a lane departurewarning system (LDW) or the like. Optionally, the display or control mayprovide a pedestrian detection alert to alert the driver of the vehicleof a pedestrian at or near the path of the vehicle. The control systemand/or vehicle may also provide a night vision system and/or objectdetection system and/or a smart forward lighting system (such as asystem that provides control and/or activation/deactivation of exteriorlights and/or interior lights of the vehicle, such as of LED lighting ofthe vehicle). The control system and/or vehicle may also or otherwiseprovide a traffic sign recognition (TSR) system and/or a seat occupancymonitoring system, and may provide an appropriate output or display oralert in response to a detection of a seat occupant (or detection of aseat being unoccupied).

Optionally, for systems having exterior mirror-mounted imaging sensorsor cameras (such as a camera at each exterior rearview mirror of thevehicle and directed so as to have a field of view generally rearwardand/or downward), the vehicle may include suitable cameras, such asJapanVue cameras with a DoD™ video display at the exterior mirrorreflector. Optionally, the exterior rearview mirror or mirrors mayinclude a display module or device, such as a video display module ofthe types described above (and optionally with thermally conductiveelement or elements at the casing or housing of the exterior rearviewmirror and in intimate contact with the display module and/or associatedcircuitry), and the display module may display video images of the scenecaptured by the cameras. For example, a display module at a driver sideexterior rearview mirror may display images captured by a camera locatedat the driver side of the vehicle or at the driver side exteriorrearview mirror, while a display module at a passenger side exteriorrearview mirror may display images captured by a camera located at thepassenger side of the vehicle or at the passenger side exterior rearviewmirror, so that the person viewing the displayed images at therespective exterior rearview mirror can readily associate the displayedimages with the captured scene at the respective side of the vehicle.Such a system may provide a 24 GHz radar side-object detection systemfor detecting objects at the side of the vehicle and generally at theblind spot at the side of the vehicle. The imaging sensors may beoperable to communicate image data to a control or video display modulevia any suitable communication protocol, and may communicate via awireless communication protocol, such as Bluetooth or the like.Optionally, the sensors or cameras and associated control may beoperable to perform tilt sensing to determine a tilt of the vehicle.

Optionally, the control or image processor of imaging system may beoperable to sense or detect precipitation at the vehicle, and mayactivate/deactivate/control the wipers of the vehicle and/or blower ofthe HVAC system and/or the like in response to rain sensing or sensingof other precipitation at the vehicle. Optionally, the vehicle may beequipped with a GOOGLE map remote video display or the like fordisplaying map information to the driver or occupant of the vehicle. Thecontrols and components of the systems described above may be located ator in the interior rearview mirror assembly and/or the exterior rearviewmirror assembly or assemblies, or may be located at a windshieldelectronics module (WEM) or the like, while remaining within the spiritand scope of the present invention.

Optionally, an interior rearview mirror of a vehicle may include atelephone function or other voice interaction system, such as a voiceactivated and/or voice instructional navigational system or the like.Such voice interaction systems and hands free systems are often desiredin vehicles to reduce the distraction to the driver of the vehicleduring use of the telephone or navigation system (and may utilizeaspects of the mirror systems described in U.S. Pat. Nos. 6,420,975 and6,906,632, which are hereby incorporated herein by reference in theirentireties). Optionally, a voice interaction system may be incorporatedinto a mirror assembly having a telephone function or navigation systemor the like. The voice interaction system may include voice recognitioncapabilities and, thus, may recognize spoken words or numbers as spokenor vocalized by the driver or occupant of the vehicle, and may includeconversational voice recognition capabilities and, thus, may recognizewords or phrases or conversations spoken or vocalized by the driver ofoccupant of the vehicle.

Many vehicles manufactured today include a global positioning systemthat is operable to determine (via satellite signals) where the vehicleis geographically located at any given time. The vehicle may include avehicle-based global positioning system that receives satellite signalsand determines the geographical location of the vehicle or the vehiclemay include a telematics system that receives the geographical locationdata or information from a remote or central service center or the like.

Technology exists that can digitize a person's voice and can dissect andreassemble portions of words or sounds to create or form or vocalizewords. Thus, a digitized audible signal may be generated that soundslike a real person talking and not like a typical recording ofindividual words or phrases. Optionally, an interior rearview mirrorassembly or system of the present invention may include a voiceinteraction system that provides such a digitized vocal output orartificially generated human voice so that the vocal or audible signalsounds similar to a person talking so that the vocal information isreadily heard and understood by the driver or occupant of the vehicle.Thus, different voice messages or information (such as in response to avoice input from the driver or occupant of the vehicle) may be readilyprovided by reassembling the digitized sounds so that the driver oroccupant of the vehicle will experience voice interaction that issimilar to a “normal” conversation. For example, the driver may say “Iwant to call Jim”, and the mirror system may respond “Do you want tocall Jim Smith or Jim Johnson?”, with the audible output or phrasegenerated by the system sounds similar to a person talking and not as ifeach word were independently recorded and assembled in that order. Thesystem thus may provide conversational voice recognition and aconversational interaction system to enhance the experience of thedriver or occupant that is using the voice interaction system of themirror or vehicle.

Optionally, the voice interaction mirror system of the present inventionmay provide different voice outputs, as may be selected by the user oras may be determined or selected by the system in response to one ormore inputs or characteristics, as discussed below. For example, thevoice interaction mirror system may provide the voice output as adifferent accent, which may be regionalized, such as an Eastern UnitedStates accent or a Southern United States accent or the like. The systemmay automatically change the voice output to a different accent, such asin response to the current or actual geographical location of thevehicle (such as in response to an input from a global positioningsystem, such as a vehicle-based global positioning system and/ornavigational system), or the accent may be selected by the user (such asvia a user input, such as a button or selection input or vocal input orthe like), or the accent may be selected depending on where the vehicleis manufactured or sold or depending on any other suitable or desiredcharacteristic or input. Thus, if the system automatically changes theaccent in response to the global positioning system (i.e. the systemprovides a regionalized accent or output), the vocal output of themirror may change as the vehicle is driven between different regions,such as from the Midwest to the South or other regional changes.Optionally, the spoken language of the voice output may change from onelanguage (such as English) to another language (such as Spanish orFrench), such as in response to the current geographical location of thevehicle (such as in response to an input from a global positioningsystem as the vehicle is driven into Mexico or a French-Canadianprovince or the like, or into other countries, such as in Europe orelsewhere), or the language may be selected by the user (such as via auser input, such as a button or selection input or vocal input or thelike), or the language may be selected depending on where the vehicle ismanufactured or sold or depending on any other suitable or desiredcharacteristic or input.

Optionally, the accent or language being output by the mirror system maybe based on one or more biometric characteristics of the driver oroccupant of the vehicle or user of the mirror system. For example, aperson may enter or select their desired accent or language, and thesystem may store that selection and use that selected accent or languagein response to the system recognizing that person in the vehicle or inthe driver's seat (such as via recognition of a biometric characteristicof the person, such as a voice recognition or retinal scan orfingerprint or other recognizable or discernible biometriccharacteristic). For example, the mirror system may generate a male (orfemale) voice output when it is determined that a male occupant is usingthe system and a female (or male) voice output when it is determinedthat a female occupant is using the system.

Optionally, and desirably, any such default output of the system orautomatic selection by the system (in response to biometriccharacteristics or user inputs or vehicle location or the like) may beoverridden by the user. Thus, the current user may override the vocaloutput and select a desired or selected voice output or accent orlanguage irrespective of the other factors such as stored selections,geographical location of the vehicle or the like. Thus, the mirrorsystem avoids the potential that one or more of the different accents orlanguages provided may become annoying to the driver and may irritate ordistract the driver during operation of the mirror system.

Such voice activated/voice interaction telematics systems thus provide adesired or appropriate audio signal to the driver of the vehicle andprovide audio feedback to the driver. However, such systems are notsuitable for drivers that are hearing impaired or deaf, such that thesedrivers may not be able to utilize the full safety features of thevehicle. It is thus envisioned that the mirror system of the presentinvention may include a display at the mirror (such as a display ondemand transflective display that is viewable at and through thereflective element of the vehicle, such as by utilizing aspects of themirror assemblies discussed above). The mirror system may include a textconverter that converts the voice output of the system to a text messagethat is displayed at the mirror display (or optionally at a displaylocated at another location within the vehicle), so that the informationbeing audibly conveyed is also or otherwise textually shown at thedisplay for viewing by the driver or occupant of the vehicle. The textconverter feature may be incorporated into the mirror system or into thevehicle or may be provided as an option by the automaker (or as anafter-market device) for hearing impaired consumers. Optionally, thetext converter and display feature may be provided via a remote serviceprovider or telematics system or the like.

Optionally, the mirror system may be capable of recognizing lip movementby the driver of the vehicle and may convert the detected and recognizedlip movement to an audible message or output, such as for a telephonefunction of the vehicle. For example, the mirror system may include acamera or imaging sensor (which may be located at the interior rearviewmirror assembly) having a field of view generally toward or at a headregion for a typical vehicle driver, and the system may have an imageprocessor that processes the images to determine and discern lipmovement and determine what is being spoken or “mouthed” by the driver.The system may then convert the lip movement interpretation to anaudible output and may generate the audible output for a telephonefunction, such that the driver (such as a deaf or hearing impaireddriver) may have a teleconference in the vehicle.

Therefore, the present invention may provide an enhanced video mirrorsystem and/or a hands free or voice acquisition or vocal interactionmirror system for a vehicle. The vocal interaction mirror system mayprovide a desired or selected artificially generated or digitized voice(with a desired or selected or appropriate accent or language or thelike) to enhance the experience to the user of the mirror system. Forexample, the voice interaction system of the vehicle may include anartificially generated human voice for providing information to thedriver of the vehicle, with the artificially generated human voice beingselectively generated with a regional accent that is determined by theactual geographic location of the vehicle, such as may be determined bya vehicle-based navigational system. Optionally, the mirror system orvocal interaction system may also provide capabilities that allow thesystem to be used by hearing impaired or deaf drivers or occupants, andmay allow such users to utilize a telephone function of the mirrorsystem or vehicle. Although described herein as being located at aninterior rearview mirror assembly of the vehicle, the vocal interactionsystem and/or display system and/or lip reading system of the presentinvention may be located elsewhere at the vehicle, and/or may beprovided to the vehicle via a remote service provider or station, whileremaining within the spirit and scope of the present invention.

Changes and modifications to the specifically described embodiments maybe carried out without departing from the principles of the presentinvention, which is intended to be limited only by the scope of theappended claims as interpreted according to the principles of patentlaw.

The invention claimed is:
 1. A vision system for a vehicle, said visionsystem comprising: a plurality of vehicular cameras located atrespective portions of a vehicle equipped with said vision system; saidplurality of vehicular cameras comprising a forward-viewing cameralocated at a front portion of the equipped vehicle, said forward-viewingcamera having a field of view at least forward of the equipped vehicle,said forward-viewing camera operable to capture first image dataexteriorly and forwardly of the equipped vehicle when the equippedvehicle normally travels forwardly; wherein said forward-viewing camerais located within the interior cabin of the equipped vehicle and isdisposed behind a windshield of the equipped vehicle and views to theexterior of the equipped vehicle through the windshield; said pluralityof vehicular cameras comprising a rear backup camera located at the rearof the equipped vehicle, said rear backup camera having a field of viewat least rearward of the equipped vehicle, said rear backup cameraoperable to capture second image data exteriorly and rearward of theequipped vehicle; a common image processor operable for processing firstimage data captured by said forward-viewing camera and second image datacaptured by said rear backup camera, wherein said common image processorutilizes object detection software during processing of first image datacaptured by said forward-viewing camera and second image data capturedby said rear backup camera; wherein said object detection softwareutilized by said common image processor utilizes an edge detectionalgorithm to detect objects present exterior the equipped vehicle; avideo display screen located within the interior cabin of the equippedvehicle viewable by a driver of the equipped vehicle when operating theequipped vehicle; wherein said video display screen comprises a backlitpixelated video display screen; wherein said video display screen isbacklit by a plurality of white light emitting light-emitting diodes,and wherein said plurality of white light emitting light-emitting diodesis operable to generate a backlighting intensity of greater than 10,000candelas per square meter; wherein said video display screen is operableto display video images with an intensity greater than 200 candelas persquare meter as viewed by the driver of the equipped vehicle; whereinlight emanating from said video display screen when displaying videoimages to be viewed by the driver of the equipped vehicle comprises atleast one of (i) circularly polarized light and (ii) ellipticallypolarized light; wherein, responsive to the equipped vehicle beingshifted into a reverse gear and while the driver of the equipped vehicleis executing a reversing maneuver, video images derived from secondimage data captured by at least said rear backup camera are displayed onsaid video display screen; and wherein, when the equipped vehicle istravelling forward, said common image processor processes first imagedata captured by said forward-viewing camera for a lane departurewarning system of the equipped vehicle and for at least one of (i) aheadlamp control system of the equipped vehicle and (ii) a traffic signrecognition system of the equipped vehicle.
 2. The vision system ofclaim 1, wherein, responsive at least in part to processing of firstimage data captured by said forward-viewing camera and second image datacaptured by said rear backup camera by said common image processor, thedriver of the equipped vehicle is alerted to the presence of an objectexterior the equipped vehicle.
 3. The vision system of claim 2, whereinsaid forward-viewing camera is located in an interior rearview mirrorassembly that is attached to the windshield and is accommodated at or bya mounting portion of said interior rearview mirror assembly.
 4. Thevision system of claim 3, wherein said common image processor is locatedin said interior rearview mirror assembly.
 5. The vision system of claim1, wherein said forward-viewing camera is accommodated by an accessorymodule mounted at the windshield of the equipped vehicle at a locationseparate and spaced from a windshield location where an interiorrearview mirror assembly mounts at the windshield.
 6. The vision systemof claim 5, wherein said common image processor is accommodated by saidaccessory module.
 7. The vision system of claim 1, wherein said videodisplay screen comprises a polarizer and a diffuser.
 8. The visionsystem of claim 1, wherein said video display screen is disposed in aninterior rearview mirror assembly of the equipped vehicle, and whereinvideo images displayed by said video display screen are viewable througha mirror reflector of a reflective element of said interior rearviewmirror assembly by the driver of the equipped vehicle when the driver isoperating the equipped vehicle, and wherein said video display screen ispart of a video display unit, and wherein said vision system furthercomprises a thermally conductive element in thermal contact with anelement of said video display unit, and wherein said thermallyconductive element at least partially draws heat generated by said videodisplay unit during operation of said video display unit to draw heataway from said video display unit.
 9. The vision system of claim 8,wherein said thermally conductive element comprises a thermallyconductive polymeric material, and wherein said thermally conductiveelement is disposed at a rear casing portion of said interior rearviewmirror assembly and is formed so as to be at least partially hidden fromview at said rear casing portion, said thermally conductive elementbeing at least one of molded, contoured, painted and coated to reducethe discernibility of said thermally conductive element at said rearcasing portion, and wherein said reflective element of said interiorrearview mirror assembly comprises an electro-optic reflective elementhaving a front substrate and a rear substrate and an electro-opticmedium disposed between said front and rear substrates, and wherein saidmirror reflector comprises a transflective mirror reflector disposed ata front surface of said rear substrate that opposes said electro-opticmedium, and wherein a transflective polarizing element is disposed at arear of said electro-optic reflective element and between said videodisplay screen and said electro-optic reflective element, and whereinsaid transflective polarizing element is disposed only at a display areain front of said video display screen, and wherein a surroundingnon-display area of said rear of said electro-optic reflective elementhas a reflective layer disposed thereat.
 10. The vision system of claim9, wherein said video display screen is operated as part of a voiceinteraction system of the equipped vehicle, said voice interactionsystem including an artificially generated human voice for providinginformation to the driver of the equipped vehicle, said artificiallygenerated human voice being selectively generated with a regional accentthat is determined by the actual geographic location of the equippedvehicle as determined by a vehicle-based navigational system.
 11. Thevision system of claim 10, wherein said video display screen comprises areflective polarizer.
 12. The vision system of claim 1, wherein, whenthe equipped vehicle is traveling forward, said common image processorprocesses first image data for the headlamp control system of theequipped vehicle.
 13. The vision system of claim 12, wherein, when theequipped vehicle is traveling forward, said common image processorprocesses first image data for the traffic sign recognition system ofthe equipped vehicle.
 14. The vision system of claim 1, wherein thedetected objects present exterior the equipped vehicle comprise at leastone vehicle present exterior the equipped vehicle.
 15. The vision systemof claim 14, wherein the detected objects present exterior the equippedvehicle comprise at least one bicycle present exterior the equippedvehicle.
 16. The vision system of claim 1, wherein said video displayscreen comprises a backlit thin film transistor liquid crystal displayvideo display screen.
 17. The vision system of claim 16, wherein saidbacklit thin film transistor liquid crystal display video display screenis backlit by said plurality of white light emitting light-emittingdiodes.
 18. The vision system of claim 17, wherein said video displayscreen is controlled, at least in part, by at least one of a videodecoder and a scalar.
 19. The vision system of claim 17, wherein saidvideo display screen comprises at least one brightness enhancement film.20. The vision system of claim 17, wherein said plurality of vehicularcameras comprises a driver-side camera located in a driver-side exteriorrearview mirror assembly of the equipped vehicle, said driver-sidecamera having a field of view at least sideward of the equipped vehicleand operable to capture third image data exteriorly and sideward of theequipped vehicle, and wherein said plurality of vehicular camerascomprises a passenger-side camera located in a passenger-side exteriorrearview mirror assembly of the equipped vehicle, said passenger-sidecamera having a field of view at least sideward of the equipped vehicleand operable to capture fourth image data exteriorly and sideward of theequipped vehicle.
 21. A vision system for a vehicle, said vision systemcomprising: a plurality of vehicular cameras located at respectiveportions of a vehicle equipped with said vision system; said pluralityof vehicular cameras comprising a forward-viewing camera located at afront portion of the equipped vehicle, said forward-viewing camerahaving a field of view at least forward of the equipped vehicle, saidforward-viewing camera operable to capture first image data exteriorlyand forwardly of the equipped vehicle when the equipped vehicle normallytravels forwardly; wherein said forward-viewing camera is located withinthe interior cabin of the equipped vehicle and is disposed behind awindshield of the equipped vehicle and views to the exterior of theequipped vehicle through the windshield; said plurality of vehicularcameras comprising a rear backup camera located at the rear of theequipped vehicle, said rear backup camera having a field of view atleast rearward of the equipped vehicle, said rear backup camera operableto capture second image data exteriorly and rearward of the equippedvehicle; said plurality of vehicular cameras comprising a driver-sidecamera located at a driver-side side portion of the equipped vehicle,said driver-side camera having a field of view at least sideward of theequipped vehicle and operable to capture third image data exteriorly andsideward of the equipped vehicle; said plurality of vehicular camerascomprising a passenger-side camera located at a passenger-side sideportion of the equipped vehicle, said passenger-side camera having afield of view at least sideward of the equipped vehicle and operable tocapture fourth image data exteriorly and sideward of the equippedvehicle; a common image processor operable for processing first imagedata captured by said forward-viewing camera, second image data capturedby said rear backup camera, third image data captured by saiddriver-side camera and fourth image data captured by said passenger-sidecamera, wherein said common image processor utilizes object detectionsoftware during processing of first image data captured by saidforward-viewing camera, second image data captured by said rear backupcamera, third image data captured by said driver-side camera and fourthimage data captured by said passenger-side camera; wherein said objectdetection software utilized by said common image processor utilizes anedge detection algorithm to detect objects present exterior the equippedvehicle; a video display screen located within the interior cabin of theequipped vehicle viewable by a driver of the equipped vehicle whenoperating the equipped vehicle; wherein said video display screencomprises a backlit pixelated video display screen; wherein said videodisplay screen is backlit by a plurality of white light emittinglight-emitting diodes, and wherein said plurality of white lightemitting light-emitting diodes is operable to generate a backlightingintensity of greater than 10,000 candelas per square meter; wherein saidvideo display screen is operable to display video images with anintensity greater than 200 candelas per square meter as viewed by thedriver of the equipped vehicle; wherein light emanating from said videodisplay screen when displaying video images to be viewed by the driverof the equipped vehicle comprises at least one of (i) circularlypolarized light and (ii) elliptically polarized light; wherein,responsive to the equipped vehicle being shifted into a reverse gear andwhile the driver of the equipped vehicle is executing a reversingmaneuver, video images derived from second image data captured by atleast said rear backup camera are displayed on said video displayscreen; wherein said forward-viewing camera is accommodated by anaccessory module mounted at the windshield of the equipped vehicle at alocation separate and spaced from a windshield location where aninterior rearview mirror assembly mounts at the windshield; and wherein,when the equipped vehicle is traveling forward, said common imageprocessor processes first image data captured by said forward-viewingcamera for a lane departure warning system of the equipped vehicle andfor a headlamp control system of the equipped vehicle.
 22. The visionsystem of claim 21, wherein said video display screen comprises at leastone brightness enhancement film.
 23. The vision system of claim 22,wherein said video display screen comprises a polarizer and a diffuser.24. The vision system of claim 23, wherein said video display screencomprises a reflective polarizer.
 25. The vision system of claim 24,wherein said video display screen comprises a backlit thin filmtransistor liquid crystal display video display screen.
 26. The visionsystem of claim 25, wherein, when the equipped vehicle is travelingforward, said common image processor processes first image data capturedby said forward-viewing camera for a traffic sign recognition system ofthe equipped vehicle.
 27. The vision system of claim 26, wherein saidcommon image processor is accommodated by said accessory module.
 28. Thevision system of claim 25, wherein the driver-side camera located at thedriver-side side portion of the equipped vehicle is in a driver-sideexterior rearview mirror assembly of the equipped vehicle.
 29. Thevision system of claim 28, wherein the passenger-side camera located atthe passenger-side side portion of the equipped vehicle is in apassenger-side exterior rearview mirror assembly of the equippedvehicle.
 30. A vision system for a vehicle, said vision systemcomprising: a plurality of vehicular cameras located at respectiveportions of a vehicle equipped with said vision system; said pluralityof vehicular cameras comprising a forward-viewing camera located at afront portion of the equipped vehicle, said forward-viewing camerahaving a field of view at least forward of the equipped vehicle, saidforward-viewing camera operable to capture first image data exteriorlyand forwardly of the equipped vehicle when the equipped vehicle normallytravels forwardly; wherein said forward-viewing camera is located withinthe interior cabin of the equipped vehicle and is disposed behind awindshield of the equipped vehicle and views to the exterior of theequipped vehicle through the windshield; said plurality of vehicularcameras comprising a rear backup camera located at the rear of theequipped vehicle, said rear backup camera having a field of view atleast rearward of the equipped vehicle, said rear backup camera operableto capture second image data exteriorly and rearward of the equippedvehicle; said plurality of vehicular cameras comprising a driver-sidecamera located at a driver-side side portion of the equipped vehicle,said driver-side camera having a field of view at least sideward of theequipped vehicle and operable to capture third image data exteriorly andsideward of the equipped vehicle; said plurality of vehicular camerascomprising a passenger-side camera located at a passenger-side sideportion of the equipped vehicle, said passenger-side camera having afield of view at least sideward of the equipped vehicle and operable tocapture fourth image data exteriorly and sideward of the equippedvehicle; a common image processor operable for processing first imagedata captured by said forward-viewing camera, second image data capturedby said rear backup camera, third image data captured by saiddriver-side camera and fourth image data captured by said passenger-sidecamera, wherein said common image processor utilizes object detectionsoftware during processing of first image data captured by saidforward-viewing camera, second image data captured by said rear backupcamera, third image data captured by said driver-side camera and fourthimage data captured by said passenger-side camera; wherein said objectdetection software utilized by said common image processor utilizes anedge detection algorithm to detect objects present exterior the equippedvehicle; a video display screen located within the interior cabin of theequipped vehicle viewable by a driver of the equipped vehicle whenoperating the equipped vehicle; wherein said video display screencomprises a backlit pixelated video display screen; wherein said videodisplay screen is backlit by a plurality of white light emittinglight-emitting diodes, and wherein said plurality of white lightemitting light-emitting diodes is operable to generate a backlightingintensity of greater than 10,000 candelas per square meter; wherein saidvideo display screen is operable to display video images with anintensity greater than 200 candelas per square meter as viewed by thedriver of the equipped vehicle; wherein light emanating from said videodisplay screen when displaying video images to be viewed by the driverof the equipped vehicle comprises at least one of (i) circularlypolarized light and (ii) elliptically polarized light; wherein,responsive to the equipped vehicle being shifted into a reverse gear andwhile the driver of the equipped vehicle is executing a reversingmaneuver, video images derived from second image data captured by atleast said rear backup camera are displayed on said video displayscreen; wherein, when the equipped vehicle is travelling forward, saidcommon image processor processes first image data captured by saidforward-viewing camera for a lane departure warning system of theequipped vehicle and a headlamp control system of the equipped vehicle;wherein said forward-viewing camera is accommodated by an accessorymodule mounted at the windshield of the equipped vehicle at a locationseparate and spaced from a windshield location where an interiorrearview mirror assembly mounts at the windshield; and wherein thedetected objects present exterior the equipped vehicle comprise at leastone vehicle present exterior the equipped vehicle.
 31. The vision systemof claim 30, wherein said video display screen comprises at least onebrightness enhancement film.
 32. The vision system of claim 31, whereinsaid video display screen comprises a polarizer and a diffuser.
 33. Thevision system of claim 32, wherein said video display screen comprises areflective polarizer.
 34. The vision system of claim 32, wherein saidvideo display screen comprises a backlit thin film transistor liquidcrystal display video display screen.
 35. The vision system of claim 32,wherein, when the equipped vehicle is traveling forward, said commonimage processor processes first image data for a traffic signrecognition system of the equipped vehicle.
 36. The vision system ofclaim 32, wherein said common image processor is accommodated by saidaccessory module.
 37. The vision system of claim 32, wherein thedriver-side camera located at the driver-side side portion of theequipped vehicle is in a driver-side exterior rearview mirror assemblyof the equipped vehicle.
 38. The vision system of claim 37, wherein thepassenger-side camera located at the passenger-side side portion of theequipped vehicle is in a passenger-side exterior rearview mirrorassembly of the equipped vehicle.
 39. The vision system of claim 38,wherein the detected objects present exterior the equipped vehiclecomprise at least one bicycle present exterior the equipped vehicle.